FFmpeg 4.0.2 + SDL2-2.0.8 實現H264解碼後播放
阿新 • • 發佈：2018-11-06
一、初級版
功能：實現了簡易視訊播放器的功能，能解碼H264後播放
工具：FFmpeg 4.0.2 + SDL2-2.0.8
C++程式碼：
/*************************************
功能：H264解碼為YUV序列,通過SDL播放
FFmpeg：4.0.2
*************************************/
#define SDL_MAIN_HANDLED
#include <iostream>
extern "C"
{
#include <libavcodec/avcodec.h>
#include <libavformat/avformat.h> 實現效果如圖所示：
二、升級版
/*************************************
功能：H264解碼為YUV序列,通過SDL播放
FFmpeg：4.0.2
新增：新增SDL Event，SDL視窗可以任意拖動
*************************************/
#define SDL_MAIN_HANDLED
#include <iostream>
extern "C"
{
#include <libavcodec/avcodec.h>
#include <libavformat/avformat.h>
#include <libswscale/swscale.h>
#include <libavfilter/avfilter.h>
#include <libavutil/imgutils.h>
#include <SDL.h>
#include <SDL_main.h>
};
using namespace std;
//Refresh Event
#define SFM_REFRESH_EVENT (SDL_USEREVENT + 1)
#define SFM_BREAK_EVENT (SDL_USEREVENT + 2)
int thread_exit = 0;
int thread_pause = 0;
int sfp_refresh_thread(void *opaque)
{
thread_exit = 0;
thread_pause = 0;
while (!thread_exit)
{
if (!thread_pause)
{
SDL_Event event;
event.type = SFM_REFRESH_EVENT;
SDL_PushEvent(&event);
}
SDL_Delay(40);
}
thread_exit = 0;
thread_pause = 0;
//Break
SDL_Event event;
event.type = SFM_BREAK_EVENT;
SDL_PushEvent(&event);
return 0;
}
static void decode(AVCodecContext *dec_ctx, AVPacket *pkt, AVFrame *pFrame, AVFrame *yuvFrame, struct SwsContext *imgCtx, FILE *outfile)
{
int ret;
/* send the packet with the compressed data to the decoder */
ret = avcodec_send_packet(dec_ctx, pkt);
if (ret < 0)
{
fprintf(stderr, "Error submitting the packet to the decoder\n");
exit(1);
}
/* read all the output frames (in general there may be any number of them */
while (ret >= 0)
{
ret = avcodec_receive_frame(dec_ctx, pFrame);
if (ret == AVERROR(EAGAIN) || ret == AVERROR_EOF)
return;
else if (ret < 0)
{
fprintf(stderr, "Error during decoding\n");
exit(1);
}
cout << "decoding the frame " << dec_ctx->frame_number << endl;
sws_scale(imgCtx, pFrame->data, pFrame->linesize, 0, dec_ctx->height, yuvFrame->data, yuvFrame->linesize);
int y_size = dec_ctx->width*dec_ctx->height;
fwrite(yuvFrame->data[0], 1, y_size, outfile); // Y
fwrite(yuvFrame->data[1], 1, y_size / 4, outfile); // U
fwrite(yuvFrame->data[2], 1, y_size / 4, outfile); // V
}
}
int DecodeH264ToYUV(const char *H264FileName, const char *YUVFileName)
{
//SDL---------------------------------------------------------------
int screen_w = 0, screen_h = 0;
SDL_Window *screen;
SDL_Renderer* sdlRenderer;
SDL_Texture* sdlTexture;
SDL_Rect sdlRect;
SDL_Thread *video_tid;
SDL_Event event;
//SDL---------------------------------------------------------------
FILE *fp_yuv = NULL;
fopen_s(&fp_yuv, YUVFileName, "wb+");
// 開啟h264檔案，並把檔案資訊存入fctx中
int iRes = 0;
AVFormatContext *fctx = avformat_alloc_context();
if ((iRes = avformat_open_input(&fctx, H264FileName, NULL, NULL)) != 0)
{
cout << "File open failed!" << endl;
return -1;
}
// 尋找視訊流資訊
if (avformat_find_stream_info(fctx, NULL) < 0)
{
cout << "Stream find failed!\n";
return -1;
}
// dump除錯資訊
av_dump_format(fctx, -1, H264FileName, NULL);
// 打開了視訊並且獲取了視訊流 ，設定視訊索引值預設值
int vindex = -1;
for (int i = 0; i < fctx->nb_streams; i++)
{
if (fctx->streams[i]->codecpar->codec_type == AVMEDIA_TYPE_VIDEO)
vindex = i;
}
// 如果沒有找到視訊的索引，說明並不是一個視訊檔案
if (vindex == -1)
{
cout << "Codec find failed!" << endl;
return -1;
}
// 分配解碼器上下文空間
AVCodecContext *cctx = avcodec_alloc_context3(NULL);
// 獲取編解碼器上下文資訊
if (avcodec_parameters_to_context(cctx, fctx->streams[vindex]->codecpar) < 0)
{
cout << "Copy stream failed!" << endl;
return -1;
}
// 查詢解碼器
AVCodec *c = avcodec_find_decoder(cctx->codec_id);
if (!c)
{
cout << "Find Decoder failed!" << endl;
return -1;
}
// 開啟解碼器
if (avcodec_open2(cctx, c, NULL) != 0) {
cout << "Open codec failed!" << endl;
return -1;
}
// 對圖形進行寬度上方的裁剪，以便於顯示得更好
struct SwsContext *imgCtx = sws_getContext(cctx->width, cctx->height, cctx->pix_fmt,
cctx->width, cctx->height, AV_PIX_FMT_YUV420P, SWS_BICUBIC, NULL, NULL, NULL);
if (!imgCtx)
{
cout << "Get swscale context failed!" << endl;
return -1;
}
//SDL Init--------------------------------------------------------------------------------------------------------------------------------
if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO | SDL_INIT_TIMER))
{
cout << "Could not initialize SDL - " << SDL_GetError() << endl;
return -1;
}
screen_w = cctx->width;
screen_h = cctx->height;
//SDL 2.0 Support for multiple windows
screen = SDL_CreateWindow("FFmpeg Player", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, screen_w, screen_h, SDL_WINDOW_OPENGL);
if (!screen)
{
cout << "SDL: could not create window - exiting:" << SDL_GetError() << endl;
return -1;
}
sdlRenderer = SDL_CreateRenderer(screen, -1, 0);
//IYUV: Y + U + V (3 planes)
//YV12: Y + V + U (3 planes)
sdlTexture = SDL_CreateTexture(sdlRenderer, SDL_PIXELFORMAT_IYUV, SDL_TEXTUREACCESS_STREAMING, cctx->width, cctx->height);
sdlRect.x = 0;
sdlRect.y = 0;
sdlRect.w = screen_w;
sdlRect.h = screen_h;
video_tid = SDL_CreateThread(sfp_refresh_thread, NULL, NULL);//SDL事件響應執行緒
//SDL Init End-----------------------------------------------------------------------------------------------------------------------------
// 初始化已解碼幀
AVPacket *pkt = av_packet_alloc();
AVFrame *pFrame = av_frame_alloc();
// 初始化解碼得到的yuv幀
AVFrame *yuvFrame = av_frame_alloc();
int vsize = av_image_get_buffer_size(AV_PIX_FMT_YUV420P, cctx->width, cctx->height, 1);
uint8_t *buf = (uint8_t *)av_malloc(vsize);
av_image_fill_arrays(yuvFrame->data, yuvFrame->linesize, buf, AV_PIX_FMT_YUV420P, cctx->width, cctx->height, 1);
// 迴圈讀取每一幀
while (av_read_frame(fctx, pkt) >= 0)
{
if (pkt->stream_index == vindex)
{
/*
if ((iRes = avcodec_send_packet(cctx, pkt)) != 0)
{
cout << "Send video stream packet failed!" << endl;
av_strerror(iRes, errbuf, 256);
return -5;
}
if ((iRes = avcodec_receive_frame(cctx, pFrame)) != 0)
{
cout << "Receive video frame failed!" << endl;
av_strerror(iRes, errbuf, 256);
return -6;
}
cout << "decoding the frame " << cctx->frame_number << endl;
sws_scale(imgCtx, pFrame->data, pFrame->linesize, 0, cctx->height, yuvFrame->data, yuvFrame->linesize);
int y_size = cctx->width*cctx->height;
fwrite(yuvFrame->data[0], 1, y_size, fp_yuv); // Y
fwrite(yuvFrame->data[1], 1, y_size / 4, fp_yuv); // U
fwrite(yuvFrame->data[2], 1, y_size / 4, fp_yuv); // V
*/
decode(cctx, pkt, pFrame, yuvFrame, imgCtx, fp_yuv);
//SDL-----------------------------------------------------------------------------------------------------
SDL_UpdateYUVTexture(sdlTexture, &sdlRect, yuvFrame->data[0], yuvFrame->linesize[0],
yuvFrame->data[1], yuvFrame->linesize[1], yuvFrame->data[2], yuvFrame->linesize[2]);
SDL_RenderClear(sdlRenderer);
SDL_RenderCopy(sdlRenderer, sdlTexture, NULL, &sdlRect);
SDL_RenderPresent(sdlRenderer);
SDL_Delay(40);
//SDL End--------------------------------------------------------------------------------------------------
}
// SDL事件
SDL_WaitEvent(&event);
if (event.type == SDL_KEYDOWN)
{
//Pause
if (event.key.keysym.sym == SDLK_SPACE)
thread_pause = !thread_pause;
}
else if (event.type == SDL_QUIT)
{
thread_exit = 1;
}
else if (event.type == SFM_BREAK_EVENT)
{
break;
}
}
/* flush the decoder */
pkt->data = NULL;
pkt->size = 0;
decode(cctx, pkt, pFrame, yuvFrame, imgCtx, fp_yuv);
//SDL---------------------------------------------------------------------------------------------------------------
SDL_UpdateYUVTexture(sdlTexture, &sdlRect, yuvFrame->data[0], yuvFrame->linesize[0],
yuvFrame->data[1], yuvFrame->linesize[1], yuvFrame->data[2], yuvFrame->linesize[2]);
SDL_RenderClear(sdlRenderer);
SDL_RenderCopy(sdlRenderer, sdlTexture, NULL, &sdlRect);
SDL_RenderPresent(sdlRenderer);
SDL_Delay(40);
SDL_Quit();
//SDL End-----------------------------------------------------------------------------------------------------------
//釋放記憶體
av_free(buf);
av_frame_free(&yuvFrame);
av_frame_free(&pFrame);
av_packet_free(&pkt);
sws_freeContext(imgCtx);
avcodec_free_context(&cctx);
avformat_close_input(&fctx);
avformat_free_context(fctx);
return 0;
}
int main()
{
const char *H264FileName = "../H264/test.h264";
const char *YUVFileName = "../YUV/test.yuv";
if (DecodeH264ToYUV(H264FileName, YUVFileName) < 0)
cout << "Decode failed!" << endl;
cout << "Decode finished!" << endl;
return getchar();
}