C語言使用ffmpeg實現(xiàn)單線程異步的視頻播放器
更新時間：2022年12月16日 10:22:46 作者：CodeOfCC
這篇文章主要為大家詳細(xì)介紹了C語言如何使用ffmpeg實現(xiàn)單線程異步的視頻播放器功能，文中的示例代碼講解詳細(xì)，感興趣的小伙伴可以嘗試一下
前言
ffplay是一個不錯的播放器，是基于多線程實現(xiàn)的，播放視頻時一般至少有4個線程：讀包線程、視頻解碼線程、音頻解碼線程、視頻渲染線程。如果需要多路播放時，線程不可避免的有點多，比如需要播放8路視頻時則需要32個線程，這樣對性能的消耗還是比較大的。于是想到用單線程實現(xiàn)一個播放器，經(jīng)過實踐發(fā)現(xiàn)是可行的，播放本地文件時可以做到完全單線程、播放網(wǎng)絡(luò)流時需要一個線程實現(xiàn)讀包異步。
一、播放流程
二、關(guān)鍵實現(xiàn)
因為是基于單線程的播放器有些細(xì)節(jié)還是要注意的。
1.視頻
（1）解碼
解碼時需要注意設(shè)置多線程解碼或者硬解以確保解碼速度，因為在單線程中解碼過慢則會導(dǎo)致視頻卡頓。
//使用多線程解碼
if (!av_dict_get(opts, "threads", NULL, 0))
av_dict_set(&opts, "threads", "auto", 0);
//打開解碼器
if (avcodec_open2(decoder->codecContext, codec, &opts) < 0) {
LOG_ERROR("Could not open codec");
av_dict_free(&opts);
return ERRORCODE_DECODER_OPENFAILED;
}
或者根據(jù)情況設(shè)置硬解碼器
codec = avcodec_find_decoder_by_name("hevc_qsv");
//打開解碼器
if (avcodec_open2(decoder->codecContext, codec, &opts) < 0) {
LOG_ERROR("Could not open codec");
av_dict_free(&opts);
return ERRORCODE_DECODER_OPENFAILED;
}
2、音頻
（1）修正時鐘
雖然音頻的播放是基于流的，時鐘也可以按照播放的數(shù)據(jù)量計算，但是出現(xiàn)丟包或者定位的一些情況時，按照數(shù)據(jù)量累計的方式會導(dǎo)致時鐘不正確，所以在解碼后的數(shù)據(jù)放入播放隊列時應(yīng)該進(jìn)行時鐘修正。
synchronize_setClockTime參考《c語言 將音視頻時鐘同步封裝成通用模塊》。在音頻解碼之后：
//讀取解碼的音頻幀 av_fifo_generic_read(play->audio.decoder.fifoFrame, &frame, sizeof(AVFrame*), NULL); //同步(修正)時鐘 AVRational timebase = play->formatContext->streams[audio->decoder.streamIndex]->time_base; //當(dāng)前幀的時間戳 double pts = (double)frame->pts * timebase.num / timebase.den; //減去播放隊列剩余數(shù)據(jù)的時長就是當(dāng)前的音頻時鐘 pts -= (double)av_audio_fifo_size(play->audio.playFifo) / play->audio.spec.freq; synchronize_setClockTime(&play->synchronize, &play->synchronize.audio, pts); //同步(修正)時鐘--end //寫入播放隊列 av_audio_fifo_write(play->audio.playFifo, (void**)&data, samples);
3、時鐘同步
需要時鐘同步的地方有3處，一處是音頻解碼后即上面的2、（1）。另外兩處則是音頻播放和視頻渲染的地方。
（1）音頻播放
synchronize_updateAudio參考《c語言 將音視頻時鐘同步封裝成通用模塊》。
//sdl音頻回調(diào)
static void audio_callback(void* userdata, uint8_t* stream, int len) {
Play* play = (Play*)userdata;
//需要寫入的數(shù)據(jù)量
samples = play->audio.spec.samples;
//時鐘同步，獲取應(yīng)該寫入的數(shù)據(jù)量，如果是同步到音頻，則需要寫入的數(shù)據(jù)量始終等于應(yīng)該寫入的數(shù)據(jù)量。
samples = synchronize_updateAudio(&play->synchronize, samples, play->audio.spec.freq);
//略
}
（2）視頻播放
在視頻渲染處實現(xiàn)如下代碼，其中synchronize_updateVideo參考《c語言 將音視頻時鐘同步封裝成通用模塊》。
//---------------時鐘同步--------------
AVRational timebase = play->formatContext->streams[video->decoder.streamIndex]->time_base;
//計算視頻幀的pts
double pts = frame->pts * (double)timebase.num / timebase.den;
//視頻幀的持續(xù)時間
double duration = frame->pkt_duration * (double)timebase.num / timebase.den;
double delay = synchronize_updateVideo(&play->synchronize, pts, duration);
if (delay > 0)
//延時
{
play->wakeupTime = getCurrentTime() + delay;
return 0;
}
else if (delay < 0)
//丟幀
{
av_fifo_generic_read(video->decoder.fifoFrame, &frame, sizeof(AVFrame*), NULL);
av_frame_unref(frame);
av_frame_free(&frame);
return 0;
}
else
//播放
{
av_fifo_generic_read(video->decoder.fifoFrame, &frame, sizeof(AVFrame*), NULL);
}
//---------------時鐘同步-------------- end4、異步讀包
如果是本地文件單線程播放是完全沒有問題的。但是播放網(wǎng)絡(luò)流時，由于av_read_frame不是異步的，網(wǎng)絡(luò)狀況差時會導(dǎo)致延時過高影響到其他部分功能的正常進(jìn)行，所以只能是將讀包的操作放到子線程執(zhí)行，這里采用async、await的思想實現(xiàn)異步。
（1）async
將av_read_frame的放到線程池中執(zhí)行。
//異步讀取包，子線程中調(diào)用此方法
static int packet_readAsync(void* arg)
{
Play* play = (Play*)arg;
play->eofPacket = av_read_frame(play->formatContext, &play->packet);
//回到播放線程處理包
play_beginInvoke(play, packet_readAwait, play);
return 0;
}
（2）await
執(zhí)行完成后通過消息隊列通知播放器線程，將后續(xù)操作放在播放線程中執(zhí)行
//異步讀取包完成后的操作
static int packet_readAwait(void* arg)
{
Play* play = (Play*)arg;
if (play->eofPacket == 0)
{
if (play->packet.stream_index == play->video.decoder.streamIndex)
//寫入視頻包隊
{
AVPacket* packet = av_packet_clone(&play->packet);
av_fifo_generic_write(play->video.decoder.fifoPacket, &packet, sizeof(AVPacket*), NULL);
}
else if (play->packet.stream_index == play->audio.decoder.streamIndex)
//寫入音頻包隊
{
AVPacket* packet = av_packet_clone(&play->packet);
av_fifo_generic_write(play->audio.decoder.fifoPacket, &packet, sizeof(AVPacket*), NULL);
}
av_packet_unref(&play->packet);
}
else if (play->eofPacket == AVERROR_EOF)
{
play->eofPacket = 1;
//寫入空包flush解碼器中的緩存
AVPacket* packet = &play->packet;
if (play->audio.decoder.fifoPacket)
av_fifo_generic_write(play->audio.decoder.fifoPacket, &packet, sizeof(AVPacket*), NULL);
if (play->video.decoder.fifoPacket)
av_fifo_generic_write(play->video.decoder.fifoPacket, &packet, sizeof(AVPacket*), NULL);
}
else
{
LOG_ERROR("read packet erro!\n");
play->exitFlag = 1;
play->isAsyncReading = 0;
return ERRORCODE_PACKET_READFRAMEFAILED;
}
play->isAsyncReading = 0;
return 0;
}
（3）消息處理
在播放線程中調(diào)用如下方法，處理事件，當(dāng)await方法拋入消息隊列后，就可以通過消息循環(huán)獲取await方法在播放線程中執(zhí)行。
//事件處理
static void play_eventHandler(Play* play) {
PlayMessage msg;
while (messageQueue_poll(&play->mq, &msg)) {
switch (msg.type)
{
case PLAYMESSAGETYPE_INVOKE:
SDL_ThreadFunction fn = (SDL_ThreadFunction)msg.param1;
fn(msg.param2);
break;
}
}
}
三、完整代碼
完整代碼c和c++都可以運行，使用ffmpeg4.3、sdl2。
main.c/cpp
#include <stdio.h>
#include <stdint.h>
#include "SDL.h"
#include<stdint.h>
#include<string.h>
#ifdef __cplusplus
extern "C" {
#endif
#include "libavformat/avformat.h"
#include "libavcodec/avcodec.h"
#include "libswscale/swscale.h"
#include "libavutil/imgutils.h"
#include "libavutil/avutil.h"
#include "libavutil/time.h"
#include "libavutil/audio_fifo.h"
#include "libswresample/swresample.h"
#ifdef __cplusplus
}
#endif
/************************************************************************
* @Project: play
* @Decription: 視頻播放器
* 這是一個播放器，基于單線程實現(xiàn)的播放器。如果是播放本地文件可以做到完全單線程，播放網(wǎng)絡(luò)流則讀取包的時候是異步的，當(dāng)然
* 主流程依然是單線程。目前是讀取包始終異步，未作判斷本地文件同步讀包處理。
* @Verision: v0.0.0
* @Author: Xin Nie
* @Create: 2022/12/12 21:21:00
* @LastUpdate: 2022/12/12 21:21:00
************************************************************************
* Copyright @ 2022. All rights reserved.
************************************************************************/
/// <summary>
/// 消息隊列
/// </summary>
typedef struct {
//隊列長度
int _capacity;
//消息對象大小
int _elementSize;
//隊列
AVFifoBuffer* _queue;
//互斥變量
SDL_mutex* _mtx;
//條件變量
SDL_cond* _cv;
}MessageQueue;
/// <summary>
/// 對象池
/// </summary>
typedef struct {
//對象緩存
void* buffer;
//對象大小
int elementSize;
//對象個數(shù)
int arraySize;
//對象使用狀態(tài)1使用，0未使用
int* _arrayUseState;
//互斥變量
SDL_mutex* _mtx;
//條件變量
SDL_cond* _cv;
}OjectPool;
/// <summary>
/// 線程池
/// </summary>
typedef struct {
//最大線程數(shù)
int maxThreadCount;
//線程信息對象池
OjectPool _pool;
}ThreadPool;
/// <summary>
/// 線程信息
/// </summary>
typedef struct {
//所屬線程池
ThreadPool* _threadPool;
//線程句柄
SDL_Thread* _thread;
//消息隊列
MessageQueue _queue;
//線程回調(diào)方法
SDL_ThreadFunction _fn;
//線程回調(diào)參數(shù)
void* _arg;
}ThreadInfo;
//解碼器
typedef struct {
//解碼上下文
AVCodecContext* codecContext;
//解碼器
const AVCodec* codec;
//解碼臨時幀
AVFrame* frame;
//包隊列
AVFifoBuffer* fifoPacket;
//幀隊列
AVFifoBuffer* fifoFrame;
//流下標(biāo)
int streamIndex;
//解碼結(jié)束標(biāo)記
int eofFrame;
}Decoder;
/// <summary>
/// 時鐘對象
/// </summary>
typedef struct {
//起始時間
double startTime;
//當(dāng)前pts
double currentPts;
}Clock;
/// <summary>
/// 時鐘同步類型
/// </summary>
typedef enum {
//同步到音頻
SYNCHRONIZETYPE_AUDIO,
//同步到視頻
SYNCHRONIZETYPE_VIDEO,
//同步到絕對時鐘
SYNCHRONIZETYPE_ABSOLUTE
}SynchronizeType;
/// <summary>
/// 時鐘同步對象
/// </summary>
typedef struct {
/// <summary>
/// 音頻時鐘
/// </summary>
Clock audio;
/// <summary>
/// 視頻時鐘
/// </summary>
Clock video;
/// <summary>
/// 絕對時鐘
/// </summary>
Clock absolute;
/// <summary>
/// 時鐘同步類型
/// </summary>
SynchronizeType type;
/// <summary>
/// 估算的視頻幀時長
/// </summary>
double estimateVideoDuration;
/// <summary>
/// 估算視頻幀數(shù)
/// </summary>
double n;
}Synchronize;
//視頻模塊
typedef struct {
//解碼器
Decoder decoder;
//輸出格式
enum AVPixelFormat forcePixelFormat;
//重采樣對象
struct SwsContext* swsContext;
//重采樣緩存
uint8_t* swsBuffer;
//渲染器
SDL_Renderer* sdlRenderer;
//紋理
SDL_Texture* sdlTexture;
//窗口
SDL_Window* screen;
//窗口寬
int screen_w;
//窗口高
int screen_h;
//旋轉(zhuǎn)角度
double angle;
//播放結(jié)束標(biāo)記
int eofDisplay;
//播放開始標(biāo)記
int sofDisplay;
}Video;
//音頻模塊
typedef struct {
//解碼器
Decoder decoder;
//輸出格式
enum AVSampleFormat forceSampleFormat;
//音頻設(shè)備id
SDL_AudioDeviceID audioId;
//期望的音頻設(shè)備參數(shù)
SDL_AudioSpec wantedSpec;
//實際的音頻設(shè)備參數(shù)
SDL_AudioSpec spec;
//重采樣對象
struct SwrContext* swrContext;
//重采樣緩存
uint8_t* swrBuffer;
//播放隊列
AVAudioFifo* playFifo;
//播放隊列互斥鎖
SDL_mutex* mutex;
//累積的待播放采樣數(shù)
int accumulateSamples;
//音量
int volume;
//聲音混合buffer
uint8_t* mixBuffer;
//播放結(jié)束標(biāo)記
int eofPlay;
//播放開始標(biāo)記
int sofPlay;
}Audio;
//播放器
typedef struct {
//視頻url
char* url;
//解復(fù)用上下文
AVFormatContext* formatContext;
//包
AVPacket packet;
//是否正在讀取包
int isAsyncReading;
//包讀取結(jié)束標(biāo)記
int eofPacket;
//視頻模塊
Video video;
//音頻模塊
Audio audio;
//時鐘同步
Synchronize synchronize;
//延時結(jié)束時間
double wakeupTime;
//播放一幀
int step;
//是否暫停
int isPaused;
//是否循環(huán)
int isLoop;
//退出標(biāo)記
int exitFlag;
//消息隊列
MessageQueue mq;
}Play;
//播放消息類型
typedef enum {
//調(diào)用方法
PLAYMESSAGETYPE_INVOKE
}PlayMessageType;
//播放消息
typedef struct {
PlayMessageType type;
void* param1;
void* param2;
}PlayMessage;
//格式映射
static const struct TextureFormatEntry {
enum AVPixelFormat format;
int texture_fmt;
} sdl_texture_format_map[] = {
{ AV_PIX_FMT_RGB8, SDL_PIXELFORMAT_RGB332 },
{ AV_PIX_FMT_RGB444, SDL_PIXELFORMAT_RGB444 },
{ AV_PIX_FMT_RGB555, SDL_PIXELFORMAT_RGB555 },
{ AV_PIX_FMT_BGR555, SDL_PIXELFORMAT_BGR555 },
{ AV_PIX_FMT_RGB565, SDL_PIXELFORMAT_RGB565 },
{ AV_PIX_FMT_BGR565, SDL_PIXELFORMAT_BGR565 },
{ AV_PIX_FMT_RGB24, SDL_PIXELFORMAT_RGB24 },
{ AV_PIX_FMT_BGR24, SDL_PIXELFORMAT_BGR24 },
{ AV_PIX_FMT_0RGB32, SDL_PIXELFORMAT_RGB888 },
{ AV_PIX_FMT_0BGR32, SDL_PIXELFORMAT_BGR888 },
{ AV_PIX_FMT_NE(RGB0, 0BGR), SDL_PIXELFORMAT_RGBX8888 },
{ AV_PIX_FMT_NE(BGR0, 0RGB), SDL_PIXELFORMAT_BGRX8888 },
{ AV_PIX_FMT_RGB32, SDL_PIXELFORMAT_ARGB8888 },
{ AV_PIX_FMT_RGB32_1, SDL_PIXELFORMAT_RGBA8888 },
{ AV_PIX_FMT_BGR32, SDL_PIXELFORMAT_ABGR8888 },
{ AV_PIX_FMT_BGR32_1, SDL_PIXELFORMAT_BGRA8888 },
{ AV_PIX_FMT_YUV420P, SDL_PIXELFORMAT_IYUV },
{ AV_PIX_FMT_YUYV422, SDL_PIXELFORMAT_YUY2 },
{ AV_PIX_FMT_UYVY422, SDL_PIXELFORMAT_UYVY },
{ AV_PIX_FMT_NONE, SDL_PIXELFORMAT_UNKNOWN },
};
/// <summary>
/// 錯誤碼
/// </summary>
typedef enum {
//無錯誤
ERRORCODE_NONE = 0,
//播放
ERRORCODE_PLAY_OPENINPUTSTREAMFAILED = -0xffff,//打開輸入流失敗
ERRORCODE_PLAY_VIDEOINITFAILED,//視頻初始化失敗
ERRORCODE_PLAY_AUDIOINITFAILED,//音頻初始化失敗
ERRORCODE_PLAY_LOOPERROR,//播放循環(huán)錯誤
ERRORCODE_PLAY_READPACKETERROR,//解包錯誤
ERRORCODE_PLAY_VIDEODECODEERROR,//視頻解碼錯誤
ERRORCODE_PLAY_AUDIODECODEERROR,//音頻解碼錯誤
ERRORCODE_PLAY_VIDEODISPLAYERROR,//視頻播放錯誤
ERRORCODE_PLAY_AUDIOPLAYERROR,//音頻播放錯誤
//解包
ERRORCODE_PACKET_CANNOTOPENINPUTSTREAM,//無法代碼輸入流
ERRORCODE_PACKET_CANNOTFINDSTREAMINFO,//查找不到流信息
ERRORCODE_PACKET_DIDNOTFINDDANYSTREAM,//找不到任何流
ERRORCODE_PACKET_READFRAMEFAILED,//讀取包失敗
//解碼
ERRORCODE_DECODER_CANNOTALLOCATECONTEXT,//解碼器上下文申請內(nèi)存失敗
ERRORCODE_DECODER_SETPARAMFAILED,//解碼器上下文設(shè)置參數(shù)失敗
ERRORCODE_DECODER_CANNOTFINDDECODER,//找不到解碼器
ERRORCODE_DECODER_OPENFAILED,//打開解碼器失敗
ERRORCODE_DECODER_SENDPACKEDFAILED,//解碼失敗
ERRORCODE_DECODER_MISSINGASTREAMTODECODE,//缺少用于解碼的流
//視頻
ERRORCODE_VIDEO_DECODERINITFAILED,//音頻解碼器初始化失敗
ERRORCODE_VIDEO_CANNOTGETSWSCONTEX,//無法獲取ffmpeg swsContext
ERRORCODE_VIDEO_IMAGEFILLARRAYFAILED,//將圖像數(shù)據(jù)映射到數(shù)組時失敗：av_image_fill_arrays
ERRORCODE_VIDEO_CANNOTRESAMPLEAFRAME,//無法重采樣視頻幀
ERRORCODE_VIDEO_MISSINGSTREAM,//缺少視頻流
//音頻
ERRORCODE_AUDIO_DECODERINITFAILED,//音頻解碼器初始化失敗
ERRORCODE_AUDIO_UNSUPORTDEVICESAMPLEFORMAT,//不支持音頻設(shè)備采樣格式
ERRORCODE_AUDIO_SAMPLESSIZEINVALID,//采樣大小不合法
ERRORCODE_AUDIO_MISSINGSTREAM,//缺少音頻流
ERRORCODE_AUDIO_SWRINITFAILED,//ffmpeg swr重采樣對象初始化失敗
ERRORCODE_AUDIO_CANNOTCONVERSAMPLE,//音頻重采樣失敗
ERRORCODE_AUDIO_QUEUEISEMPTY,//隊列數(shù)據(jù)為空
//幀
ERRORCODE_FRAME_ALLOCFAILED,//初始化幀失敗
//隊列
ERRORCODE_FIFO_ALLOCFAILED,//初始化隊列失敗
//sdl
ERRORCODE_SDL_INITFAILED,//sdl初始化失敗
ERRORCODE_SDL_CANNOTCREATEMUTEX,//無法創(chuàng)建互斥鎖
ERRORCODE_SDL_CANNOTOPENDEVICE, //無法打開音頻設(shè)備
ERRORCODE_SDL_CREATEWINDOWFAILED,//創(chuàng)建窗口失敗
ERRORCODE_SDL_CREATERENDERERFAILED,//創(chuàng)建渲染器失敗
ERRORCODE_SDL_CREATETEXTUREFAILED,//創(chuàng)建紋理失敗
//內(nèi)存
ERRORCODE_MEMORY_ALLOCFAILED,//申請內(nèi)存失敗
ERRORCODE_MEMORY_LEAK,//內(nèi)存泄漏
//參數(shù)
ERRORCODE_ARGUMENT_INVALID,//參數(shù)不合法
ERRORCODE_ARGUMENT_OUTOFRANGE,//超出范圍
}ErrorCode;
/// <summary>
/// 日志等級
/// </summary>
typedef enum {
LOGLEVEL_NONE = 0,
LOGLEVEL_INFO = 1,
LOGLEVEL_DEBUG = 2,
LOGLEVEL_TRACE = 4,
LOGLEVEL_WARNNING = 8,
LOGLEVEL_ERROR = 16,
LOGLEVEL_ALL = LOGLEVEL_INFO | LOGLEVEL_DEBUG | LOGLEVEL_TRACE | LOGLEVEL_WARNNING | LOGLEVEL_ERROR
}
LogLevel;
//輸出日志
#define LOGHELPERINTERNALLOG(message,level,...) aclog(__FILE__,__FUNCTION__,__LINE__,level,message,##__VA_ARGS__)
#define LOG_INFO(message,...) LOGHELPERINTERNALLOG(message,LOGLEVEL_INFO, ##__VA_ARGS__)
#define LOG_DEBUG(message,...) LOGHELPERINTERNALLOG(message,LOGLEVEL_DEBUG,##__VA_ARGS__)
#define LOG_TRACE(message,...) LOGHELPERINTERNALLOG(cmessage,LOGLEVEL_TRACE,##__VA_ARGS__)
#define LOG_WARNNING(message,...) LOGHELPERINTERNALLOG(message,LOGLEVEL_WARNNING,##__VA_ARGS__)
#define LOG_ERROR(message,...) LOGHELPERINTERNALLOG(message,LOGLEVEL_ERROR,##__VA_ARGS__)
static int logLevelFilter = LOGLEVEL_ALL;
static ThreadPool* _pool = NULL;
//寫日志
void aclog(const char* fileName, const char* methodName, int line, LogLevel level, const char* message, ...) {
if ((logLevelFilter & level) == 0)
return;
char dateTime[32];
time_t tt = time(0);
struct tm* t;
va_list valist;
char buf[512];
char* pBuf = buf;
va_start(valist, message);
int size = vsnprintf(pBuf, sizeof(buf), message, valist);
if (size > sizeof(buf))
{
pBuf = (char*)av_malloc(size + 1);
vsnprintf(pBuf, size + 1, message, valist);
}
va_end(valist);
t = localtime(&tt);
sprintf(dateTime, "%04d-%02d-%02d %02d:%02d:%02d", t->tm_year + 1900, t->tm_mon + 1, t->tm_mday, t->tm_hour, t->tm_min, t->tm_sec);
//在此處可替換為寫文件
printf("%s %d %d %s %s %d: %s\n", dateTime, level, SDL_ThreadID(), fileName, methodName, line, pBuf);
if (pBuf != buf)
av_free(pBuf);
}
//日志過濾，設(shè)為LOGLEVEL_NONE則不輸出日志
void setLogFilter(LogLevel level) {
logLevelFilter = level;
}
//初始化消息隊列
int messageQueue_init(MessageQueue* _this, int capacity, int elementSize) {
_this->_queue = av_fifo_alloc(elementSize * capacity);
if (!_this->_queue)
return ERRORCODE_MEMORY_ALLOCFAILED;
_this->_mtx = SDL_CreateMutex();
if (!_this->_mtx)
return ERRORCODE_MEMORY_ALLOCFAILED;
_this->_cv = SDL_CreateCond();
if (!_this->_cv)
return ERRORCODE_MEMORY_ALLOCFAILED;
_this->_capacity = capacity;
_this->_elementSize = elementSize;
return 0;
}
//反初始化消息隊列
void messageQueue_deinit(MessageQueue* _this) {
if (_this->_queue)
av_fifo_free(_this->_queue);
if (_this->_cv)
SDL_DestroyCond(_this->_cv);
if (_this->_mtx)
SDL_DestroyMutex(_this->_mtx);
memset(_this, 0, sizeof(MessageQueue));
}
//推入消息
int messageQueue_push(MessageQueue* _this, void* msg) {
int ret = 0;
SDL_LockMutex(_this->_mtx);
ret = av_fifo_generic_write(_this->_queue, msg, _this->_elementSize, NULL);
SDL_CondSignal(_this->_cv);
SDL_UnlockMutex(_this->_mtx);
return ret > 0;
}
//輪詢序消息
int messageQueue_poll(MessageQueue* _this, void* msg) {
SDL_LockMutex(_this->_mtx);
int size = av_fifo_size(_this->_queue);
if (size >= _this->_elementSize)
{
av_fifo_generic_read(_this->_queue, msg, _this->_elementSize, NULL);
}
SDL_UnlockMutex(_this->_mtx);
return size;
}
//等待消息
void messageQueue_wait(MessageQueue* _this, void* msg) {
SDL_LockMutex(_this->_mtx);
while (1) {
int size = av_fifo_size(_this->_queue);
if (size >= _this->_elementSize)
{
av_fifo_generic_read(_this->_queue, msg, _this->_elementSize, NULL);
break;
}
SDL_CondWait(_this->_cv, _this->_mtx);
}
SDL_UnlockMutex(_this->_mtx);
}
//初始化對象池
int ojectPool_init(OjectPool* _this, void* bufferArray, int elementSize, int arraySize)
{
if (elementSize < 1 || arraySize < 1)
return ERRORCODE_ARGUMENT_INVALID;
_this->buffer = (unsigned char*)bufferArray;
_this->elementSize = elementSize;
_this->arraySize = arraySize;
_this->_arrayUseState = (int*)av_mallocz(sizeof(int) * arraySize);
if (!_this->_arrayUseState)
return ERRORCODE_MEMORY_ALLOCFAILED;
_this->_mtx = SDL_CreateMutex();
if (!_this->_mtx)
return ERRORCODE_MEMORY_ALLOCFAILED;
_this->_cv = SDL_CreateCond();
if (!_this->_cv)
return ERRORCODE_MEMORY_ALLOCFAILED;
return 0;
}
//反初始化對象池
void objectPool_deinit(OjectPool* _this)
{
av_free(_this->_arrayUseState);
if (_this->_cv)
SDL_DestroyCond(_this->_cv);
if (_this->_mtx)
SDL_DestroyMutex(_this->_mtx);
memset(_this, 0, sizeof(OjectPool));
}
//取出對象
void* objectPool_take(OjectPool* _this, int timeout) {
void* element = NULL;
SDL_LockMutex(_this->_mtx);
while (1)
{
for (int i = 0; i < _this->arraySize; i++)
{
if (!_this->_arrayUseState[i])
{
element = &((Uint8*)_this->buffer)[i * _this->elementSize];
_this->_arrayUseState[i] = 1;
break;
}
}
if (!element)
{
if (timeout == -1)
{
int ret = SDL_CondWait(_this->_cv, _this->_mtx);
if (ret == -1)
{
LOG_ERROR("SDL_CondWait error");
break;
}
}
else
{
int ret = SDL_CondWaitTimeout(_this->_cv, _this->_mtx, timeout);
if (ret != 0)
{
if (ret == -1)
{
LOG_ERROR("SDL_CondWait error");
}
break;
}
}
}
else
{
break;
}
}
SDL_UnlockMutex(_this->_mtx);
return element;
}
//歸還對象
void objectPool_restore(OjectPool* _this, void* element) {
SDL_LockMutex(_this->_mtx);
for (int i = 0; i < _this->arraySize; i++)
{
if (_this->_arrayUseState[i] && &((Uint8*)_this->buffer)[i * _this->elementSize] == element)
{
SDL_CondSignal(_this->_cv);
_this->_arrayUseState[i] = 0;
break;
}
}
SDL_UnlockMutex(_this->_mtx);
}
//初始化線程池
int threadPool_init(ThreadPool* _this, int maxThreadCount) {
_this->maxThreadCount = maxThreadCount;
return ojectPool_init(&_this->_pool, av_mallocz(sizeof(ThreadInfo) * maxThreadCount), sizeof(ThreadInfo), maxThreadCount);
}
//反初始化線程池
void threadPool_denit(ThreadPool* _this) {
ThreadInfo* threads = (ThreadInfo*)_this->_pool.buffer;
if (threads)
{
for (int i = 0; i < _this->maxThreadCount; i++)
{
int status;
if (threads[i]._thread)
{
int msg = 0;
messageQueue_push(&threads[i]._queue, &msg);
SDL_WaitThread(threads[i]._thread, &status);
messageQueue_deinit(&threads[i]._queue);
}
}
}
av_freep(&_this->_pool.buffer);
objectPool_deinit(&_this->_pool);
}
//線程池，線程處理過程
int threadPool_threadProc(void* data)
{
ThreadInfo* info = (ThreadInfo*)data;
int msg = 1;
while (msg) {
info->_fn(info->_arg);
objectPool_restore(&info->_threadPool->_pool, info);
messageQueue_wait(&info->_queue, &msg);
}
return 0;
}
//在線程池中運行方法
void threadPool_run(ThreadPool* _this, SDL_ThreadFunction fn, void* arg) {
ThreadInfo* info = (ThreadInfo*)objectPool_take(&_this->_pool, -1);
info->_fn = fn;
info->_arg = arg;
if (info->_thread)
{
int msg = 1;
messageQueue_push(&info->_queue, &msg);
}
else
{
info->_threadPool = _this;
messageQueue_init(&info->_queue, 1, sizeof(int));
info->_thread = SDL_CreateThread(threadPool_threadProc, "threadPool_threadProc", info);
}
}
//在播放線程中運行方法
void play_beginInvoke(Play* _this, SDL_ThreadFunction fn, void* arg)
{
PlayMessage msg;
msg.type = PLAYMESSAGETYPE_INVOKE;
msg.param1 = fn;
msg.param2 = arg;
messageQueue_push(&_this->mq, &msg);
}
//#include<chrono>
/// <summary>
/// 返回當(dāng)前時間
/// </summary>
/// <returns>當(dāng)前時間，單位秒，精度微秒</returns>
static double getCurrentTime()
{
//此處用的是ffmpeg的av_gettime_relative。如果沒有ffmpeg環(huán)境，則可替換成平臺獲取時鐘的方法：單位為秒，精度需要微妙，相對絕對時鐘都可以。
return av_gettime_relative() / 1000000.0;
//return std::chrono::time_point_cast <std::chrono::nanoseconds>(std::chrono::high_resolution_clock::now()).time_since_epoch().count() / 1e+9;
}
/// <summary>
/// 重置時鐘同步
/// 通常用于暫停、定位
/// </summary>
/// <param name="syn">時鐘同步對象</param>
void synchronize_reset(Synchronize* syn) {
SynchronizeType type = syn->type;
memset(syn, 0, sizeof(Synchronize));
syn->type = type;
}
/// <summary>
/// 獲取主時鐘
/// </summary>
/// <param name="syn">時鐘同步對象</param>
/// <returns>主時鐘對象</returns>
Clock* synchronize_getMasterClock(Synchronize* syn) {
switch (syn->type)
{
case SYNCHRONIZETYPE_AUDIO:
return &syn->audio;
case SYNCHRONIZETYPE_VIDEO:
return &syn->video;
case SYNCHRONIZETYPE_ABSOLUTE:
return &syn->absolute;
default:
break;
}
return 0;
}
/// <summary>
/// 獲取主時鐘的時間
/// </summary>
/// <param name="syn">時鐘同步對象</param>
/// <returns>時間，單位s</returns>
double synchronize_getMasterTime(Synchronize* syn) {
return getCurrentTime() - synchronize_getMasterClock(syn)->startTime;
}
/// <summary>
/// 設(shè)置時鐘的時間
/// </summary>
/// <param name="syn">時鐘同步對象</param>
/// <param name="pts">當(dāng)前時間，單位s</param>
void synchronize_setClockTime(Synchronize* syn, Clock* clock, double pts)
{
clock->currentPts = pts;
clock->startTime = getCurrentTime() - pts;
}
/// <summary>
/// 獲取時鐘的時間
/// </summary>
/// <param name="syn">時鐘同步對象</param>
/// <param name="clock">時鐘對象</param>
/// <returns>時間，單位s</returns>
double synchronize_getClockTime(Synchronize* syn, Clock* clock)
{
return getCurrentTime() - clock->startTime;
}
/// <summary>
/// 更新視頻時鐘
/// </summary>
/// <param name="syn">時鐘同步對象</param>
/// <param name="pts">視頻幀pts,單位為s</param>
/// <param name="duration">視頻幀時長,單位為s。缺省值為0，內(nèi)部自動估算duration</param>
/// <returns>大于0則延時值為延時時長，等于0顯示，小于0丟幀</returns>
double synchronize_updateVideo(Synchronize* syn, double pts, double duration)
{
if (duration == 0)
//估算duration
{
if (pts != syn->video.currentPts)
syn->estimateVideoDuration = (syn->estimateVideoDuration * syn->n + pts - syn->video.currentPts) / (double)(syn->n + 1);
duration = syn->estimateVideoDuration;
//只估算最新3幀
if (syn->n++ > 3)
syn->estimateVideoDuration = syn->n = 0;
if (duration == 0)
duration = 0.1;
}
if (syn->video.startTime == 0)
{
syn->video.startTime = getCurrentTime() - pts;
}
//以下變量時間單位為s
//當(dāng)前時間
double currentTime = getCurrentTime() - syn->video.startTime;
//計算時間差,大于0則late，小于0則early。
double diff = currentTime - pts;
double sDiff = 0;
if (syn->type != SYNCHRONIZETYPE_VIDEO && synchronize_getMasterClock(syn)->startTime != 0)
//同步到主時鐘
{
sDiff = syn->video.startTime - synchronize_getMasterClock(syn)->startTime;
diff += sDiff;
}
修正時間，時鐘和視頻幀偏差超過0.1s時重新設(shè)置起點時間。
//if (diff > 0.1)
//{
// syn->video.startTime = getCurrentTime() - pts;
// currentTime = pts;
// diff = 0;
//}
//時間早了延時
if (diff < -0.001)
{
if (diff < -0.1)
{
diff = -0.1;
}
//printf("video-time：%.3lfs audio-time:%.3lfs avDiff:%.4lfms early:%.4lfms \n", getCurrentTime() - syn->video.startTime, getCurrentTime() - syn->audio.startTime, sDiff * 1000, diff * 1000);
return -diff;
}
syn->video.currentPts = pts;
//時間晚了丟幀，duration為一幀的持續(xù)時間，在一個duration內(nèi)是正常時間，加一個duration作為閾值來判斷丟幀。
if (diff > 2 * duration)
{
//printf("time:%.3lfs avDiff %.4lfms late for:%.4lfms droped\n", pts, sDiff * 1000, diff * 1000);
return -1;
}
//更新視頻時鐘
printf("video-time：%.3lfs audio-time:%.3lfs absolute-time:%.3lfs synDiff:%.4lfms diff:%.4lfms \r", pts, getCurrentTime() - syn->audio.startTime, getCurrentTime() - syn->absolute.startTime, sDiff * 1000, diff * 1000);
syn->video.startTime = getCurrentTime() - pts;
if (syn->absolute.startTime == 0)
{
syn->absolute.startTime = syn->video.startTime;
}
return 0;
}
//double lastTime = 0;
/// <summary>
/// 更新音頻時鐘
/// </summary>
/// <param name="syn">時鐘同步對象</param>
/// <param name="samples">采樣數(shù)</param>
/// <param name="samplerate">采樣率</param>
/// <returns>應(yīng)該播放的采樣數(shù)</returns>
int synchronize_updateAudio(Synchronize* syn, int samples, int samplerate) {
if (syn->type != SYNCHRONIZETYPE_AUDIO && synchronize_getMasterClock(syn)->startTime != 0)
{
//同步到主時鐘
double audioTime = getCurrentTime() - syn->audio.startTime;
double diff = 0;
diff = synchronize_getMasterTime(syn) - audioTime;
int oldSamples = samples;
if (fabs(diff) > 0.01) {
samples += diff * samplerate;
}
if (samples < 0)
{
samples = 0;
}
if (samples > oldSamples * 2)
{
samples = oldSamples * 2;
}
}
syn->audio.currentPts += (double)samples / samplerate;
syn->audio.startTime = getCurrentTime() - syn->audio.currentPts;
if (syn->absolute.startTime == 0)
{
syn->absolute.startTime = syn->audio.startTime;
}
return samples;
}
/// <summary>
/// 更新音頻時鐘，通過數(shù)據(jù)長度
/// </summary>
/// <param name="syn">時鐘同步對象</param>
/// <param name="bytesSize">數(shù)據(jù)長度</param>
/// <param name="samplerate">采樣率</param>
/// <param name="channels">聲道數(shù)</param>
/// <param name="bitsPerSample">位深</param>
/// <returns>應(yīng)該播放的數(shù)據(jù)長度</returns>
int synchronize_updateAudioByBytesSize(Synchronize* syn, size_t bytesSize, int samplerate, int channels, int bitsPerSample) {
return synchronize_updateAudio(syn, bytesSize / (channels * bitsPerSample / 8), samplerate) * (bitsPerSample / 8) * channels;
}
//初始化解碼器
static int decoder_init(Play* play, Decoder* decoder, int wantFifoPacketSize, int wantFifoFrameSize) {
//創(chuàng)建解碼上下文
decoder->codecContext = avcodec_alloc_context3(NULL);
AVDictionary* opts = NULL;
if (decoder->codecContext == NULL)
{
LOG_ERROR("Could not allocate AVCodecContext");
return ERRORCODE_DECODER_CANNOTALLOCATECONTEXT;
}
//獲取解碼器
if (avcodec_parameters_to_context(decoder->codecContext, play->formatContext->streams[decoder->streamIndex]->codecpar) < 0)
{
LOG_ERROR("Could not init AVCodecContext");
return ERRORCODE_DECODER_SETPARAMFAILED;
}
AVCodec* codec = avcodec_find_decoder(decoder->codecContext->codec_id);
if (codec == NULL) {
LOG_ERROR("Codec not found");
return ERRORCODE_DECODER_CANNOTFINDDECODER;
}
//使用多線程解碼
if (!av_dict_get(opts, "threads", NULL, 0))
av_dict_set(&opts, "threads", "auto", 0);
//打開解碼器
if (avcodec_open2(decoder->codecContext, codec, &opts) < 0) {
LOG_ERROR("Could not open codec");
av_dict_free(&opts);
return ERRORCODE_DECODER_OPENFAILED;
}
av_dict_free(&opts);
//初始化臨時幀
decoder->frame = av_frame_alloc();
if (!decoder->frame)
{
LOG_ERROR("Alloc avframe failed");
return ERRORCODE_FRAME_ALLOCFAILED;
}
//初始化包隊列
decoder->fifoPacket = av_fifo_alloc(sizeof(AVPacket*) * wantFifoPacketSize);
if (!decoder->fifoPacket)
{
LOG_ERROR("alloc packet fifo failed");
return ERRORCODE_FIFO_ALLOCFAILED;
}
//初始化幀隊列
decoder->fifoFrame = av_fifo_alloc(sizeof(AVFrame*) * wantFifoFrameSize);
if (!decoder->fifoFrame)
{
LOG_ERROR("alloc frame fifo failed");
return ERRORCODE_FIFO_ALLOCFAILED;
}
return 0;
}
//清空解碼隊列
static void decoder_clear(Play* play, Decoder* decoder) {
//清空包隊列
if (decoder->fifoPacket)
{
while (av_fifo_size(decoder->fifoPacket) > 0)
{
AVPacket* packet;
av_fifo_generic_read(decoder->fifoPacket, &packet, sizeof(AVPacket*), NULL);
if (packet != &play->packet)
{
av_packet_unref(packet);
av_packet_free(&packet);
}
}
}
//清空幀隊列
if (decoder->fifoFrame)
{
while (av_fifo_size(decoder->fifoFrame) > 0)
{
AVFrame* frame;
av_fifo_generic_read(decoder->fifoFrame, &frame, sizeof(AVFrame*), NULL);
av_frame_unref(frame);
av_frame_free(&frame);
}
}
//清空解碼器緩存
if (decoder->codecContext)
{
avcodec_flush_buffers(decoder->codecContext);
}
}
//反初始化解碼器
static void decoder_deinit(Play* play, Decoder* decoder)
{
decoder_clear(play, decoder);
if (decoder->codecContext)
{
avcodec_close(decoder->codecContext);
avcodec_free_context(&decoder->codecContext);
}
if (decoder->fifoPacket)
{
av_fifo_free(decoder->fifoPacket);
decoder->fifoPacket = NULL;
}
if (decoder->fifoFrame)
{
av_fifo_free(decoder->fifoFrame);
decoder->fifoFrame = NULL;
}
if (decoder->frame)
{
if (decoder->frame->format != -1)
{
av_frame_unref(decoder->frame);
}
av_frame_free(&decoder->frame);
}
decoder->eofFrame = 0;
}
//解碼
static int decoder_decode(Play* play, Decoder* decoder) {
int ret = 0;
AVPacket* packet = NULL;
if (decoder->streamIndex == -1)
{
LOG_ERROR("Decoder missing a stream");
return ERRORCODE_DECODER_MISSINGASTREAMTODECODE;
}
if (av_fifo_space(decoder->fifoFrame) < 1)
//幀隊列已滿
{
goto end;
}
//接收上次解碼的幀
while (avcodec_receive_frame(decoder->codecContext, decoder->frame) == 0) {
AVFrame* frame = av_frame_clone(decoder->frame);
av_frame_unref(decoder->frame);
av_fifo_generic_write(decoder->fifoFrame, &frame, sizeof(AVFrame*), NULL);
if (av_fifo_space(decoder->fifoFrame) < 1)
//幀隊列已滿
{
goto end;
}
}
if (av_fifo_size(decoder->fifoPacket) > 0)
//包隊列有數(shù)據(jù)，開始解碼
{
av_fifo_generic_read(decoder->fifoPacket, &packet, sizeof(AVPacket*), NULL);
//發(fā)送包
if (avcodec_send_packet(decoder->codecContext, packet) < 0)
{
LOG_ERROR("Decode error");
ret = ERRORCODE_DECODER_SENDPACKEDFAILED;
goto end;
}
//接收解碼的幀
while (avcodec_receive_frame(decoder->codecContext, decoder->frame) == 0) {
AVFrame* frame = av_frame_clone(decoder->frame);
av_frame_unref(decoder->frame);
av_fifo_generic_write(decoder->fifoFrame, &frame, sizeof(AVFrame*), NULL);
if (av_fifo_space(decoder->fifoFrame) < 1)
//幀隊列已滿
{
goto end;
}
}
}
if (play->eofPacket)
{
decoder->eofFrame = 1;
}
end:
if (packet && packet != &play->packet)
{
av_packet_unref(packet);
av_packet_free(&packet);
}
return ret;
}
//音頻設(shè)備播放回調(diào)
static void audio_callback(void* userdata, uint8_t* stream, int len) {
Play* play = (Play*)userdata;
int samples = 0;
//讀取隊列中的音頻數(shù)據(jù)，由于AVAudioFifo非線程安全，且是子線程觸發(fā)此回調(diào)，所以需要加鎖
SDL_LockMutex(play->audio.mutex);
if (!play->isPaused)
{
if (av_audio_fifo_size(play->audio.playFifo) >= play->audio.spec.samples)
{
int drain = 0;
//需要寫入的數(shù)據(jù)量
samples = play->audio.spec.samples;
//時鐘同步，獲取應(yīng)該寫入的數(shù)據(jù)量，如果是同步到音頻，則需要寫入的數(shù)據(jù)量始終等于應(yīng)該寫入的數(shù)據(jù)量。
samples = synchronize_updateAudio(&play->synchronize, samples, play->audio.spec.freq);
samples += play->audio.accumulateSamples;
if (samples > av_audio_fifo_size(play->audio.playFifo))
{
play->audio.accumulateSamples = samples - av_audio_fifo_size(play->audio.playFifo);
samples = av_audio_fifo_size(play->audio.playFifo);
}
else
{
play->audio.accumulateSamples = 0;
}
if (samples > play->audio.spec.samples)
//比需要寫入的數(shù)據(jù)量大，則丟棄一部分
{
drain = samples - play->audio.spec.samples;
samples = play->audio.spec.samples;
}
if (play->audio.volume + SDL_MIX_MAXVOLUME != SDL_MIX_MAXVOLUME)
//改變音量
{
if (!play->audio.mixBuffer)
{
play->audio.mixBuffer = (uint8_t*)av_malloc(len);
if (!play->audio.mixBuffer)
{
LOG_ERROR("mixBuffer alloc failed");
return;
}
}
av_audio_fifo_read(play->audio.playFifo, (void**)&play->audio.mixBuffer, samples);
int len2 = av_samples_get_buffer_size(0, play->audio.spec.channels, samples, play->audio.forceSampleFormat, 1);
memset(stream, 0, len2);
SDL_MixAudioFormat(stream, play->audio.mixBuffer, play->audio.spec.format, len2, play->audio.volume + SDL_MIX_MAXVOLUME);
}
else
//直接寫入
{
av_audio_fifo_read(play->audio.playFifo, (void**)&stream, samples);
}
av_audio_fifo_drain(play->audio.playFifo, drain);
}
}
SDL_UnlockMutex(play->audio.mutex);
//補充靜音數(shù)據(jù)
int fillSize = av_samples_get_buffer_size(0, play->audio.spec.channels, samples, play->audio.forceSampleFormat, 1);
if (fillSize < 0)
fillSize = 0;
if (len - fillSize > 0)
{
memset(stream + fillSize, 0, len - fillSize);
}
}
//初始化音頻模塊
static int audio_init(Play* play, Audio* audio) {
//初始化解碼器
if (decoder_init(play, &audio->decoder, 600, 100) != 0)
{
LOG_ERROR("audio decoder init error");
return ERRORCODE_AUDIO_DECODERINITFAILED;
}
//初始化sdl
if ((SDL_WasInit(0) & (SDL_INIT_VIDEO | SDL_INIT_AUDIO | SDL_INIT_TIMER)) == 0)
{
if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO | SDL_INIT_TIMER)) {
LOG_ERROR("Could not initialize SDL - %s", SDL_GetError());
return ERRORCODE_SDL_INITFAILED;
}
}
//打開音頻設(shè)備
audio->wantedSpec.channels = av_get_channel_layout_nb_channels(audio->decoder.codecContext->channel_layout);
audio->wantedSpec.freq = audio->decoder.codecContext->sample_rate;
audio->wantedSpec.format = AUDIO_F32SYS;
audio->wantedSpec.silence = 0;
audio->wantedSpec.samples = FFMAX(512, 2 << av_log2(audio->wantedSpec.freq / 30));
audio->wantedSpec.callback = audio_callback;
audio->wantedSpec.userdata = play;
audio->audioId = SDL_OpenAudioDevice(NULL, 0, &audio->wantedSpec, &audio->spec, SDL_AUDIO_ALLOW_ANY_CHANGE);
if (audio->audioId < 2)
{
LOG_ERROR("Open audio device error");
return ERRORCODE_SDL_CANNOTOPENDEVICE;
}
//匹配音頻格式
switch (audio->spec.format)
{
case AUDIO_S16SYS:
audio->forceSampleFormat = AV_SAMPLE_FMT_S16;
break;
case AUDIO_S32SYS:
audio->forceSampleFormat = AV_SAMPLE_FMT_S32;
break;
case AUDIO_F32SYS:
audio->forceSampleFormat = AV_SAMPLE_FMT_FLT;
break;
default:
LOG_ERROR("audio device format was not surported %d", (int)audio->spec.format);
return ERRORCODE_AUDIO_UNSUPORTDEVICESAMPLEFORMAT;
}
//初始化音頻幀隊列的互斥鎖
audio->mutex = SDL_CreateMutex();
if (!audio->mutex)
{
LOG_ERROR("alloc mutex failed");
return ERRORCODE_SDL_CANNOTCREATEMUTEX;
}
//音頻播放隊列
audio->playFifo = av_audio_fifo_alloc(audio->forceSampleFormat, audio->spec.channels, audio->spec.samples * 30);
if (!audio->playFifo)
{
LOG_ERROR("alloc audio fifo failed");
return ERRORCODE_FIFO_ALLOCFAILED;
}
//設(shè)備開啟播放
SDL_PauseAudioDevice(audio->audioId, 0);
return 0;
}
//音頻初始化
static void audio_deinit(Play* play, Audio* audio)
{
if (audio->audioId >= 2)
{
SDL_PauseAudioDevice(audio->audioId, 1);
SDL_CloseAudioDevice(audio->audioId);
audio->audioId = 0;
}
if (audio->mutex)
{
SDL_DestroyMutex(audio->mutex);
audio->mutex = NULL;
}
if (play->audio.playFifo)
{
av_audio_fifo_free(play->audio.playFifo);
play->audio.playFifo = NULL;
}
if (audio->swrContext)
{
swr_free(&audio->swrContext);
}
if (audio->swrBuffer)
{
av_freep(&audio->swrBuffer);
}
if (audio->mixBuffer)
{
av_freep(&audio->mixBuffer);
}
decoder_deinit(play, &audio->decoder);
audio->eofPlay = 0;
audio->sofPlay = 0;
}
//音頻播放
static int audio_play(Play* play, Audio* audio) {
if (audio->decoder.streamIndex == -1)
{
LOG_ERROR("audio play missing audio stream");
//沒有音頻流
return ERRORCODE_AUDIO_MISSINGSTREAM;
}
if (play->video.decoder.streamIndex != -1 && !play->video.sofDisplay)
{
return 0;
}
while (av_fifo_size(play->audio.decoder.fifoFrame) > 0)
{
AVFrame* frame = NULL;
uint8_t* data = NULL;
int dataSize = 0;
int samples = 0;
av_fifo_generic_peek(play->audio.decoder.fifoFrame, &frame, sizeof(AVFrame*), NULL);
if (play->audio.forceSampleFormat != play->audio.decoder.codecContext->sample_fmt || play->audio.spec.freq != frame->sample_rate || play->audio.spec.channels != frame->channels)
//重采樣
{
//計算輸入采樣數(shù)
int out_count = (int64_t)frame->nb_samples * play->audio.spec.freq / frame->sample_rate + 256;
//計算輸出數(shù)據(jù)大小
int out_size = av_samples_get_buffer_size(NULL, play->audio.spec.channels, out_count, play->audio.forceSampleFormat, 0);
//輸入數(shù)據(jù)指針
const uint8_t** in = (const uint8_t**)frame->extended_data;
//輸出緩沖區(qū)指針
uint8_t** out = &play->audio.swrBuffer;
int len2 = 0;
if (out_size < 0) {
LOG_ERROR("sample output size value %d was invalid", out_size);
return ERRORCODE_AUDIO_SAMPLESSIZEINVALID;
}
if (!play->audio.swrContext)
//初始化重采樣對象
{
play->audio.swrContext = swr_alloc_set_opts(NULL, av_get_default_channel_layout(play->audio.spec.channels), play->audio.forceSampleFormat, play->audio.spec.freq, play->audio.decoder.codecContext->channel_layout, play->audio.decoder.codecContext->sample_fmt, play->audio.decoder.codecContext->sample_rate, 0, NULL);
if (!play->audio.swrContext || swr_init(play->audio.swrContext) < 0) {
LOG_ERROR("swr_alloc_set_opts or swr_init failed");
return ERRORCODE_AUDIO_SWRINITFAILED;
}
}
if (!play->audio.swrBuffer)
//申請輸出緩沖區(qū)
{
play->audio.swrBuffer = (uint8_t*)av_mallocz(out_size);
if (!play->audio.swrBuffer)
{
LOG_ERROR("audio swr ouput buffer alloc failed");
return ERRORCODE_MEMORY_ALLOCFAILED;
}
}
//執(zhí)行重采樣
len2 = swr_convert(play->audio.swrContext, out, out_count, in, frame->nb_samples);
if (len2 < 0) {
LOG_ERROR("swr_convert failed");
return ERRORCODE_AUDIO_CANNOTCONVERSAMPLE;
}
//取得輸出數(shù)據(jù)
data = play->audio.swrBuffer;
//輸出數(shù)據(jù)長度
dataSize = av_samples_get_buffer_size(0, play->audio.spec.channels, len2, play->audio.forceSampleFormat, 1);
samples = len2;
}
else
//無需重采樣
{
data = frame->data[0];
dataSize = av_samples_get_buffer_size(frame->linesize, frame->channels, frame->nb_samples, play->audio.forceSampleFormat, 0);
samples = frame->nb_samples;
}
if (dataSize < 0)
{
LOG_ERROR("sample data size value %d was invalid", dataSize);
return ERRORCODE_AUDIO_SAMPLESSIZEINVALID;
}
//寫入播放隊列
SDL_LockMutex(play->audio.mutex);
if (av_audio_fifo_space(play->audio.playFifo) >= samples)
{
//同步(修正)時鐘
AVRational timebase = play->formatContext->streams[audio->decoder.streamIndex]->time_base;
//當(dāng)前幀的時間戳
double pts = (double)frame->pts * timebase.num / timebase.den;
//減去播放隊列剩余數(shù)據(jù)的時長就是當(dāng)前的音頻時鐘
pts -= (double)av_audio_fifo_size(play->audio.playFifo) / play->audio.spec.freq;
//設(shè)置音頻時鐘
synchronize_setClockTime(&play->synchronize, &play->synchronize.audio, pts);
//同步(修正)時鐘--end
//寫入播放隊列
av_audio_fifo_write(play->audio.playFifo, (void**)&data, samples);
//解碼隊列的幀出隊
av_fifo_generic_read(play->audio.decoder.fifoFrame, &frame, sizeof(AVFrame*), NULL);
av_frame_unref(frame);
av_frame_free(&frame);
if (!audio->sofPlay)
//標(biāo)記開始
{
audio->sofPlay = 1;
}
}
else
{
SDL_UnlockMutex(play->audio.mutex);
break;
}
SDL_UnlockMutex(play->audio.mutex);
}
//計算睡眠延時
SDL_LockMutex(play->audio.mutex);
double canSleepTime = (double)av_audio_fifo_size(play->audio.playFifo) / play->audio.spec.freq;
double wakeupTime = getCurrentTime() + canSleepTime;
if (play->video.decoder.streamIndex == -1 || wakeupTime < play->wakeupTime)
{
play->wakeupTime = wakeupTime;
}
SDL_UnlockMutex(play->audio.mutex);
if (av_fifo_size(play->audio.decoder.fifoFrame) < 1 && audio->decoder.eofFrame)
//標(biāo)記結(jié)束
{
audio->eofPlay = 1;
}
return 0;
}
//初始化視頻模塊
static int video_init(Play* play, Video* video) {
//初始化解碼器
if (decoder_init(play, &video->decoder, 600, 1) != 0)
{
LOG_ERROR("video decoder init error");
return ERRORCODE_VIDEO_DECODERINITFAILED;
}
//初始化sdl
if ((SDL_WasInit(0) & (SDL_INIT_VIDEO | SDL_INIT_AUDIO | SDL_INIT_TIMER)) == 0)
{
if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO | SDL_INIT_TIMER)) {
LOG_ERROR("Could not initialize SDL - %s", SDL_GetError());
return ERRORCODE_SDL_INITFAILED;
}
}
return 0;
}
//反初始化視頻模塊
static void video_deinit(Play* play, Video* video) {
if (video->swsContext)
{
sws_freeContext(video->swsContext);
video->swsContext = NULL;
}
if (video->swsBuffer)
{
av_free(video->swsBuffer);
video->swsBuffer = NULL;
}
if (video->sdlTexture)
{
SDL_DestroyTexture(video->sdlTexture);
video->sdlTexture = NULL;
}
if (video->sdlRenderer)
{
SDL_DestroyRenderer(video->sdlRenderer);
video->sdlRenderer = NULL;
}
if (video->screen)
{
SDL_DestroyWindow(video->screen);
video->screen = NULL;
}
decoder_deinit(play, &video->decoder);
video->eofDisplay = 0;
video->sofDisplay = 0;
}
double get_rotation(AVStream* st)
{
AVDictionaryEntry* rotate_tag = av_dict_get(st->metadata, "rotate", NULL, 0);
double theta = 0;
if (rotate_tag && *rotate_tag->value && strcmp(rotate_tag->value, "0")) {
theta = atof(rotate_tag->value);
}
theta -= 360 * floor(theta / 360 + 0.9 / 360);
if (fabs(theta - 90 * round(theta / 90)) > 2)
{
LOG_INFO("Odd rotation angle");
}
return theta;
}
/// <summary>
/// 計算旋轉(zhuǎn)的矩形大小
/// </summary>
/// <param name="src">原圖像區(qū)域</param>
/// <param name="dst">目標(biāo)區(qū)域</param>
/// <param name="angle">旋轉(zhuǎn)角度</param>
/// <returns></returns>
static SDL_Rect getRotateRect(SDL_Rect *srcRect, SDL_Rect* dstRect,double angle) {
SDL_Rect targetRect;
const double PI = 3.1415926535897935384626;
double theta = PI / 180.0 * angle;
//計算旋轉(zhuǎn)后的邊框大小
int width = srcRect->h * fabs(sin(theta) )+ srcRect->w * fabs(cos(theta)) + 0.5;
int height = srcRect->h * fabs(cos(theta)) + srcRect->w * fabs(sin(theta)) + 0.5;
double srcRatio = (double)srcRect->w / srcRect->h;
double srcBorderRatio = (double)width / height;
double dstRatio = (double)dstRect->w / dstRect->h;
//計算邊框縮放到目標(biāo)區(qū)域的大小
int zoomWidth;
int zoomHeight;
if (srcBorderRatio > dstRatio)
{
zoomWidth = dstRect->w;
zoomHeight = dstRect->w / srcBorderRatio;
}
else
{
zoomWidth = dstRect->h * srcBorderRatio;
zoomHeight = dstRect->h;
}
//通過縮放后的邊框計算還原的圖像大小
targetRect.h = (double)zoomWidth / (fabs(sin(theta) )+ srcRatio * fabs(cos(theta)));
targetRect.w = targetRect.h * srcRatio;
targetRect.x = (dstRect->w- targetRect.w ) / 2;
targetRect.y = (dstRect->h- targetRect.h ) / 2;
return targetRect;
}
//渲染到窗口
static int video_present(Play* play, Video* video, AVFrame* frame)
{
SDL_Rect sdlRect;
SDL_Rect sdlRect2;
uint8_t* dst_data[4];
int dst_linesize[4];
if (!video->screen)
{
//創(chuàng)建窗口
video->screen = SDL_CreateWindow("video play window", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED,
video->screen_w, video->screen_h,
SDL_WINDOW_OPENGL);
if (!video->screen) {
LOG_ERROR("SDL: could not create window - exiting:%s\n", SDL_GetError());
return ERRORCODE_SDL_CREATEWINDOWFAILED;
}
}
if (!video->sdlRenderer)
//初始化sdl紋理
{
video->angle = get_rotation(play->formatContext->streams[play->video.decoder.streamIndex]);
video->sdlRenderer = SDL_CreateRenderer(video->screen, -1, 0);
if (!video->sdlRenderer)
{
LOG_ERROR("Create sdl renderer error");
return ERRORCODE_SDL_CREATERENDERERFAILED;
}
//獲取合適的像素格式
struct TextureFormatEntry format;
format.format = AV_PIX_FMT_YUV420P;
format.texture_fmt = SDL_PIXELFORMAT_IYUV;
for (int i = 0; i < sizeof(sdl_texture_format_map) / sizeof(struct TextureFormatEntry); i++)
{
if (sdl_texture_format_map[i].format == video->decoder.codecContext->pix_fmt)
{
format = sdl_texture_format_map[i];
break;
}
}
video->forcePixelFormat = format.format;
//創(chuàng)建和視頻大小一樣的紋理
video->sdlTexture = SDL_CreateTexture(video->sdlRenderer, format.texture_fmt, SDL_TEXTUREACCESS_STREAMING, video->decoder.codecContext->width, video->decoder.codecContext->height);
if (!video->sdlTexture)
{
LOG_ERROR("Create sdl texture error");
return ERRORCODE_SDL_CREATETEXTUREFAILED;
}
}
if (video->forcePixelFormat != video->decoder.codecContext->pix_fmt)
//重采樣-格式轉(zhuǎn)換
{
video->swsContext = sws_getCachedContext(video->swsContext, video->decoder.codecContext->width, video->decoder.codecContext->height, video->decoder.codecContext->pix_fmt, video->decoder.codecContext->width, video->decoder.codecContext->height, video->forcePixelFormat, SWS_FAST_BILINEAR, NULL, NULL, NULL);
if (!video->swsContext)
{
LOG_ERROR("sws_getCachedContext failed");
return ERRORCODE_VIDEO_CANNOTGETSWSCONTEX;
}
if (!video->swsBuffer)
{
video->swsBuffer = (uint8_t*)av_malloc(av_image_get_buffer_size(video->forcePixelFormat, video->decoder.codecContext->width, video->decoder.codecContext->height, 64));
if (video->swsBuffer)
{
LOG_ERROR("audio swr ouput buffer alloc failed");
return ERRORCODE_MEMORY_ALLOCFAILED;
}
}
if (av_image_fill_arrays(dst_data, dst_linesize, video->swsBuffer, video->forcePixelFormat, video->decoder.codecContext->width, video->decoder.codecContext->height, 1) < 0)
{
LOG_ERROR("sws_getCachedContext failed");
return ERRORCODE_VIDEO_IMAGEFILLARRAYFAILED;
}
if (sws_scale(video->swsContext, frame->data, frame->linesize, 0, frame->height, dst_data, dst_linesize) < 0)
{
LOG_ERROR("Call sws_scale error");
return ERRORCODE_VIDEO_CANNOTRESAMPLEAFRAME;
}
}
else
//無需重采樣
{
memcpy(dst_data, frame->data, sizeof(uint8_t*) * 4);
memcpy(dst_linesize, frame->linesize, sizeof(int) * 4);
}
//窗口區(qū)域
sdlRect.x = 0;
sdlRect.y = 0;
sdlRect.w = video->screen_w;
sdlRect.h = video->screen_h;
//視頻區(qū)域
sdlRect2.x = 0;
sdlRect2.y = 0;
sdlRect2.w = video->decoder.codecContext->width;
sdlRect2.h = video->decoder.codecContext->height;
//渲染到sdl窗口
SDL_RenderClear(video->sdlRenderer);
SDL_UpdateYUVTexture(video->sdlTexture, &sdlRect2, dst_data[0], dst_linesize[0], dst_data[1], dst_linesize[1], dst_data[2], dst_linesize[2]);
if (video->angle == 0)
SDL_RenderCopy(video->sdlRenderer, video->sdlTexture, NULL, &sdlRect);
else
//旋轉(zhuǎn)視頻
{
SDL_Rect sdlRect3;
sdlRect3= getRotateRect(&sdlRect2,&sdlRect,video->angle);
SDL_RenderCopyEx(video->sdlRenderer, video->sdlTexture, NULL
, &sdlRect3, video->angle, 0, SDL_FLIP_NONE);
}
SDL_RenderPresent(video->sdlRenderer);
}
//視頻顯示
static int video_display(Play* play, Video* video) {
if (play->video.decoder.streamIndex == -1)
//沒有視頻流
{
return ERRORCODE_VIDEO_MISSINGSTREAM;
}
if (play->audio.decoder.streamIndex != -1 && video->sofDisplay && !play->audio.sofPlay)
return 0;
AVFrame* frame = NULL;
if (av_fifo_size(video->decoder.fifoFrame) > 0)
{
av_fifo_generic_peek(video->decoder.fifoFrame, &frame, sizeof(AVFrame*), NULL);
//---------------時鐘同步--------------
AVRational timebase = play->formatContext->streams[video->decoder.streamIndex]->time_base;
//計算視頻幀的pts
double pts = frame->pts * (double)timebase.num / timebase.den;
//視頻幀的持續(xù)時間
double duration = frame->pkt_duration * (double)timebase.num / timebase.den;
double delay = synchronize_updateVideo(&play->synchronize, pts, duration);
if (delay > 0)
//延時
{
play->wakeupTime = getCurrentTime() + delay;
return 0;
}
else if (delay < 0)
//丟幀
{
av_fifo_generic_read(video->decoder.fifoFrame, &frame, sizeof(AVFrame*), NULL);
av_frame_unref(frame);
av_frame_free(&frame);
return 0;
}
else
//播放
{
av_fifo_generic_read(video->decoder.fifoFrame, &frame, sizeof(AVFrame*), NULL);
}
//---------------時鐘同步-------------- end
}
else if (video->decoder.eofFrame)
{
video->sofDisplay = 1;
//標(biāo)記結(jié)束
video->eofDisplay = 1;
}
if (frame)
{
//渲染
video_present(play, video, frame);
av_frame_unref(frame);
av_frame_free(&frame);
if (!video->sofDisplay)
video->sofDisplay = 1;
if (play->step)
{
play->step--;
}
}
return 0;
}
static int interrupt_cb(void* arg) {
Play* play = (Play*)arg;
return play->exitFlag;
}
//打開輸入流
static int packet_open(Play* play) {
//打開輸入流
play->formatContext = avformat_alloc_context();
play->formatContext->interrupt_callback.callback = interrupt_cb;
play->formatContext->interrupt_callback.opaque = play;
if (avformat_open_input(&play->formatContext, play->url, NULL, NULL) != 0) {
LOG_ERROR("Couldn't open input stream");
return ERRORCODE_PACKET_CANNOTOPENINPUTSTREAM;
}
//查找輸入流信息
if (avformat_find_stream_info(play->formatContext, NULL) < 0) {
LOG_ERROR("Couldn't find stream information");
return ERRORCODE_PACKET_CANNOTFINDSTREAMINFO;
}
//ignore = 0;
play->video.decoder.streamIndex = -1;
//獲取視頻流
for (unsigned i = 0; i < play->formatContext->nb_streams; i++)
if (play->formatContext->streams[i]->codecpar->codec_type == AVMEDIA_TYPE_VIDEO) {
play->video.decoder.streamIndex = i;
break;
}
play->audio.decoder.streamIndex = -1;
//獲取音頻流
for (unsigned i = 0; i < play->formatContext->nb_streams; i++)
if (play->formatContext->streams[i]->codecpar->codec_type == AVMEDIA_TYPE_AUDIO) {
play->audio.decoder.streamIndex = i;
break;
}
//沒有找到任何流
if (play->video.decoder.streamIndex == -1 && play->audio.decoder.streamIndex == -1) {
LOG_ERROR("Didn't find any stream.");
return ERRORCODE_PACKET_DIDNOTFINDDANYSTREAM;
}
play->eofPacket = 0;
return 0;
}
//異步讀取包完成后的操作
static int packet_readAwait(void* arg)
{
Play* play = (Play*)arg;
if (play->eofPacket == 0)
{
if (play->packet.stream_index == play->video.decoder.streamIndex)
//寫入視頻包隊
{
AVPacket* packet = av_packet_clone(&play->packet);
av_fifo_generic_write(play->video.decoder.fifoPacket, &packet, sizeof(AVPacket*), NULL);
}
else if (play->packet.stream_index == play->audio.decoder.streamIndex)
//寫入音頻包隊
{
AVPacket* packet = av_packet_clone(&play->packet);
av_fifo_generic_write(play->audio.decoder.fifoPacket, &packet, sizeof(AVPacket*), NULL);
}
av_packet_unref(&play->packet);
}
else if (play->eofPacket == AVERROR_EOF)
{
play->eofPacket = 1;
//寫入空包flush解碼器中的緩存
AVPacket* packet = &play->packet;
if (play->audio.decoder.fifoPacket)
av_fifo_generic_write(play->audio.decoder.fifoPacket, &packet, sizeof(AVPacket*), NULL);
if (play->video.decoder.fifoPacket)
av_fifo_generic_write(play->video.decoder.fifoPacket, &packet, sizeof(AVPacket*), NULL);
}
else
{
LOG_ERROR("read packet erro!\n");
play->exitFlag = 1;
play->isAsyncReading = 0;
return ERRORCODE_PACKET_READFRAMEFAILED;
}
play->isAsyncReading = 0;
return 0;
}
//異步讀取包
static int packet_readAsync(void* arg)
{
Play* play = (Play*)arg;
play->eofPacket = av_read_frame(play->formatContext, &play->packet);
//回到播放線程處理包
play_beginInvoke(play, packet_readAwait, play);
return 0;
}
//讀取包
static int packet_read(Play* play) {
if (play->isAsyncReading)
return 0;
if (play->eofPacket)
{
return 0;
}
if (play->video.decoder.streamIndex != -1 && av_fifo_space(play->video.decoder.fifoPacket) < 1)
//視頻包隊列已滿
{
return 0;
}
if (play->audio.decoder.streamIndex != -1 && av_fifo_space(play->audio.decoder.fifoPacket) < 1)
//音頻包隊列已滿
{
return 0;
}
if (!_pool)
//初始化線程池
{
_pool = (ThreadPool*)av_mallocz(sizeof(ThreadPool));
threadPool_init(_pool, 32);
}
play->isAsyncReading = 1;
//異步讀取包
threadPool_run(_pool, packet_readAsync, play);
return 0;
}
static void play_eventHandler(Play* play);
//等待讀包結(jié)束
static void packet_waitAsyncReadFinished(Play* play) {
//確保異步操作結(jié)束
while (play->isAsyncReading)
{
av_usleep(0.01 * 1000000);
play_eventHandler(play);
}
}
//關(guān)閉輸入流
static void packet_close(Play* play) {
packet_waitAsyncReadFinished(play);
if (play->packet.data)
{
av_packet_unref(&play->packet);
}
if (play->formatContext)
{
avformat_close_input(&play->formatContext);
}
}
//定位
static int packet_seek(Play* play, double time) {
packet_waitAsyncReadFinished(play);
return avformat_seek_file(play->formatContext, -1, INT64_MIN, time * AV_TIME_BASE, INT64_MAX, 0) >= 0;
}
//設(shè)置窗口大小
void play_setWindowSize(Play* play, int width, int height) {
play->video.screen_w = width;
play->video.screen_h = height;
}
//定位
void play_seek(Play* play, double time) {
if (time < 0)
{
time = 0;
}
if (packet_seek(play, time))
{
//重置屬性
play->audio.accumulateSamples = 0;
play->audio.sofPlay = 0;
play->video.sofDisplay = 0;
//清除緩存
decoder_clear(play, &play->video.decoder);
decoder_clear(play, &play->audio.decoder);
avformat_flush(play->formatContext);
if (play->audio.playFifo)
{
SDL_LockMutex(play->audio.mutex);
av_audio_fifo_reset(play->audio.playFifo);
synchronize_reset(&play->synchronize);
SDL_UnlockMutex(play->audio.mutex);
}
else
{
synchronize_reset(&play->synchronize);
}
//暫停時需要播放一幀
play->step = 1;
}
}
//暫停
void play_pause(Play* play, int isPaused) {
if (play->isPaused == isPaused)
return;
if (!isPaused)
{
play->audio.sofPlay = 0;
play->video.sofDisplay = 0;
synchronize_reset(&play->synchronize);
}
play->isPaused = isPaused;
}
//靜音
void play_setVolume(Play* play, int value) {
//移動到0作為最大音量。則初始化memset后不需要設(shè)置默認(rèn)音量。
if (value < 0)
value = 0;
value -= SDL_MIX_MAXVOLUME;
if (play->audio.volume == value)
return;
play->audio.volume = value;
}
int play_getVolume(Play* play) {
return play->audio.volume + SDL_MIX_MAXVOLUME;
}
//事件處理
static void play_eventHandler(Play* play) {
PlayMessage msg;
while (messageQueue_poll(&play->mq, &msg)) {
switch (msg.type)
{
case PLAYMESSAGETYPE_INVOKE:
SDL_ThreadFunction fn = (SDL_ThreadFunction)msg.param1;
fn(msg.param2);
break;
}
}
//處理窗口消息
SDL_Event sdl_event;
if (SDL_PollEvent(&sdl_event))
{
switch (sdl_event.type)
{
case SDL_WINDOWEVENT:
if (sdl_event.window.event == SDL_WINDOWEVENT_CLOSE)
play->exitFlag = 1;
break;
case SDL_KEYDOWN:
switch (sdl_event.key.keysym.sym) {
case SDLK_UP:
play_setVolume(play, play_getVolume(play) + 20);
break;
case SDLK_DOWN:
play_setVolume(play, play_getVolume(play) - 20);
break;
case SDLK_LEFT:
play_seek(play, synchronize_getMasterTime(&play->synchronize) - 10);
break;
case SDLK_RIGHT:
play_seek(play, synchronize_getMasterTime(&play->synchronize) + 10);
break;
case SDLK_SPACE:
play_pause(play, !play->isPaused);
break;
default:
break;
}
break;
}
}
}
//播放循環(huán)
static int play_loop(Play* play)
{
int ret = 0;
double remainingTime = 0;
while (!play->exitFlag)
{
if (!play->isPaused || play->step)
{
//解復(fù)用
if ((ret = packet_read(play)) != 0)
{
LOG_ERROR("read packet error");
ret = ERRORCODE_PLAY_READPACKETERROR;
break;
}
//視頻解碼
if ((ret = decoder_decode(play, &play->video.decoder)) != 0)
{
LOG_ERROR("video decode error");
ret = ERRORCODE_PLAY_VIDEODECODEERROR;
break;
}
//音頻解碼
if ((ret = decoder_decode(play, &play->audio.decoder)) != 0)
{
LOG_ERROR("audio decode error");
ret = ERRORCODE_PLAY_AUDIODECODEERROR;
break;
}
//延時等待
remainingTime = (play->wakeupTime - getCurrentTime()) / 2;
if (remainingTime > 0)
{
av_usleep(remainingTime * 1000000);
}
//視頻顯示
if ((ret = video_display(play, &play->video)) != 0)
{
LOG_ERROR("video display error");
ret = ERRORCODE_PLAY_VIDEODISPLAYERROR;
break;
}
//音頻播放
if ((ret = audio_play(play, &play->audio)) != 0)
{
LOG_ERROR("audio play error");
ret = ERRORCODE_PLAY_AUDIOPLAYERROR;
break;
}
//檢查結(jié)尾
if ((play->video.decoder.streamIndex == -1 || play->video.eofDisplay) && (play->audio.decoder.streamIndex == -1 || play->audio.eofPlay))
{
if (!play->isLoop)
break;
//循環(huán)播放，定位到起點
play->eofPacket = 0;
play->audio.decoder.eofFrame = 0;
play->video.decoder.eofFrame = 0;
play->audio.eofPlay = 0;
play->video.eofDisplay = 0;
play_seek(play, 0);
continue;
}
}
else
{
av_usleep(0.01 * 1000000);
}
//處理消息
play_eventHandler(play);
}
return ret;
}
/// <summary>
/// 播放
/// 單線程阻塞播放
/// </summary>
/// <param name="play">播放器對象</param>
/// <param name="url">輸入流的地址，可以是本地路徑、http、https、rtmp、rtsp等</param>
/// <returns>錯誤碼，0表示無錯誤</returns>
int play_exec(Play* play, const char* url) {
int ret = 0;
play->url = (char*)url;
//打開輸入流
if ((ret = packet_open(play)) != 0)
{
LOG_ERROR("open input error");
ret = ERRORCODE_PLAY_OPENINPUTSTREAMFAILED;
goto end;
}
//初始化視頻模塊
if (play->video.decoder.streamIndex != -1)
{
if ((ret = video_init(play, &play->video)) != 0)
{
LOG_ERROR("init video error");
ret = ERRORCODE_PLAY_VIDEOINITFAILED;
goto end;
}
}
//初始化音頻模塊
if (play->audio.decoder.streamIndex != -1)
{
if ((ret = audio_init(play, &play->audio)) != 0)
{
LOG_ERROR("init audio error");
ret = ERRORCODE_PLAY_AUDIOINITFAILED;
goto end;
}
}
else
{
play->synchronize.type = SYNCHRONIZETYPE_ABSOLUTE;
}
//初始化消息隊列
if ((ret = messageQueue_init(&play->mq, 500, sizeof(PlayMessage))) != 0)
{
LOG_ERROR("open input error");
ret = ERRORCODE_PLAY_OPENINPUTSTREAMFAILED;
goto end;
}
//進(jìn)入播放循環(huán)進(jìn)行：解碼-渲染-播放
if ((ret = play_loop(play)) != 0)
{
ret = ERRORCODE_PLAY_LOOPERROR;
}
end:
//銷毀資源
if (play->video.decoder.streamIndex != -1)
{
video_deinit(play, &play->video);
}
if (play->audio.decoder.streamIndex != -1)
{
audio_deinit(play, &play->audio);
}
packet_close(play);
synchronize_reset(&play->synchronize);
messageQueue_deinit(&play->mq);
play->url = NULL;
play->exitFlag = 0;
return ret;
}
/// <summary>
/// 退出播放
/// </summary>
/// <param name="play">播放器對象</param>
void play_exit(Play* play)
{
play->exitFlag = 1;
}
#undef main
int main(int argc, char** argv) {
Play play;
//memset相當(dāng)于初始化
memset(&play, 0, sizeof(Play));
play_setWindowSize(&play, 640, 360);
play.isLoop = 1;
//單線程阻塞播放
return play_exec(&play, "D:\\test.mp4");
}
完整代碼項目：vs2022、makefile，Windows、Linux都可以運行，Linux需要自行配置ffmpeg和sdl
四、使用示例
#undef main
int main(int argc, char** argv) {
Play play;
//memset相當(dāng)于初始化
memset(&play, 0, sizeof(Play));
play_setWindowSize(&play, 640, 360);
play.isLoop = 1;
//單線程阻塞播放。左快退、右快進(jìn)、上下調(diào)音量、空格暫停。
return play_exec(&play, "D:\\test.mp4");
}
總結(jié)
以上就是今天要講的內(nèi)容，本文的播放器驗證了單線程播放是可行的，尤其是播放本地文件可以做到完全單線程，那這樣對于實現(xiàn)視頻剪輯工具就有很大的幫助了，每多一條軌道只需要增加一個線程。而且采用異步讀包之后也能正常播放網(wǎng)絡(luò)流，2個線程播放視頻依然比ffplay要優(yōu)化。
到此這篇關(guān)于C語言使用ffmpeg實現(xiàn)單線程異步的視頻播放器的文章就介紹到這了,更多相關(guān)C語言 ffmpeg視頻播放器內(nèi)容請搜索腳本之家以前的文章或繼續(xù)瀏覽下面的相關(guān)文章希望大家以后多多支持腳本之家！
相關(guān)文章
C++設(shè)計模式之簡單工廠模式的實現(xiàn)示例
這篇文章主要給大家介紹了關(guān)于C++設(shè)計模式之簡單工廠模式的相關(guān)資料,簡單工廠模式,主要用于創(chuàng)建對象,添加類時,不會影響以前的系統(tǒng)代碼,需要的朋友可以參考下2021-06-06
這篇文章主要為大家詳細(xì)介紹了Qt中槽的使用教程，文中的示例代碼講解詳細(xì)，對我們學(xué)習(xí)Qt有一定的幫助，感興趣的小伙伴可以跟隨小編一起學(xué)習(xí)一下2022-12-12
本篇文章是對用C++實現(xiàn)雙向循環(huán)鏈表的方法進(jìn)行了詳細(xì)的分析介紹，需要的朋友參考下2013-05-05
scanf()函數(shù)是通用終端格式化輸入函數(shù)，它從標(biāo)準(zhǔn)輸入設(shè)備(鍵盤) 讀取輸入的信息，接下來通過本文給大家介紹C語言中關(guān)于scanf讀取緩存區(qū)的問題，需要的朋友一起看看吧2021-09-09
C++允許多個函數(shù)擁有相同的名字，只要它們的參數(shù)列表不同就可以，這就是函數(shù)的重載（Function?Overloading），借助重載，一個函數(shù)名可以有多種用途2022-05-05
這篇文章主要介紹了MFC程序執(zhí)行過程,包括對MFC執(zhí)行流程的分析以及斷點調(diào)試分析出的SDI程序執(zhí)行流程,需要的朋友可以參考下2014-09-09
C/C++ Crypto密碼庫調(diào)用的實現(xiàn)方法
Crypto 庫是C/C++的加密算法庫，這個加密庫很流行，基本上涵蓋了市面上的各類加密解密算法，感興趣的可以參考一下2021-06-06
C++編譯報錯:||error: ld returned 1 exit
這篇文章主要介紹了C++編譯報錯:||error: ld returned 1 exit status|的解決方式,具有很好的參考價值,希望對大家有所幫助,如有錯誤或未考慮完全的地方,望不吝賜教2024-01-01
這篇文章主要為大家詳細(xì)介紹了OpenCV獲取視頻的每一幀，并保存為.jpg圖片，文中示例代碼介紹的非常詳細(xì)，具有一定的參考價值，感興趣的小伙伴們可以參考一下2019-07-07
模板是為了實現(xiàn)泛型編程,所謂泛型編程,就是指編寫與類型無關(guān)的代碼,下面這篇文章主要給大家介紹了關(guān)于C++模板以及實現(xiàn)vector的相關(guān)資料,需要的朋友可以參考下2021-11-11