ffmpeg 在ubuntu上编译环境搭建和开发

步骤如下：

1. 下载

官网永远是王道，呵呵：http://ffmpeg.org/download.html

或者 svn checkout svn://svn.mplayerhq.hu/ffmpeg/trunk ffmpeg

2. 编译

运行./configure
很不幸，运行configure后出现了错误提示：
yasm not found, use –disable-yasm for a crippled build

解决方案：sudo apt-getinstall yasm
重新./configure,搞定

make

make install
权限不够需要前面加上sudo

编译源码：一定注意加载库的顺序.



参考代码：

#include <SDL/SDL.h>

#include <libavcodec/avcodec.h>
#include <libavformat/avformat.h>
#include <stdio.h>
#include <libswscale/swscale.h>

int main(int argc, char *argv[]) {
AVFormatContext *pFormatCtx;
int i, videoStream;
AVCodecContext *pCodecCtx;
AVCodec *pCodec;
AVFrame *pFrame;
AVFrame *pFrameYUV;
AVPacket packet;
int frameFinished;
int numBytes;

// Register all formats and codecs
av_register_all();
// Open video file
if (av_open_input_file(&pFormatCtx, "/home/user/workspace/panda/media/video/4f5a9c384d94eb21e5273ec263457535.mp4", NULL, 0, NULL )
!= 0) {
printf("===  cannot open file\n===");
return -1; // Couldn't open file
}
// Retrieve stream information
if (av_find_stream_info(pFormatCtx) < 0)
return -1; // Couldn't find stream information
// Dump information about file onto standard error
//    dump_format(pFormatCtx, 0, argv[1], false);
// Find the first video stream
videoStream = -1;
for (i = 0; i < pFormatCtx->nb_streams; i++)
if (pFormatCtx->streams[i]->codec->codec_type == CODEC_TYPE_VIDEO) ////////
{
videoStream = i;
break;
}
if (videoStream == -1)
return -1; // Didn't find a video stream
// Get a pointer to the codec context for the video stream
pCodecCtx = pFormatCtx->streams[videoStream]->codec; //////////
///////// SDL initialization
SDL_Surface *screen = SDL_SetVideoMode(pCodecCtx->width, pCodecCtx->height, 0, SDL_HWSURFACE);
SDL_Overlay *overlay = SDL_CreateYUVOverlay(pCodecCtx->width, pCodecCtx->height, SDL_YV12_OVERLAY, screen);
static SDL_Rect rect;
rect.x = 0;
rect.y = 0;
rect.w = pCodecCtx->width;
rect.h = pCodecCtx->height;
//////////
// Find the decoder for the video stream
pCodec = avcodec_find_decoder(pCodecCtx->codec_id);
if (pCodec == NULL )
return -1; // Codec not found
// Open codec
if (avcodec_open(pCodecCtx, pCodec) < 0)
return -1; // Could not open codec

// Allocate video frame
pFrame = avcodec_alloc_frame();
// Allocate an AVFrame structure
pFrameYUV = avcodec_alloc_frame();
if (pFrameYUV == NULL )
return -1;

static struct SwsContext *img_convert_ctx;

img_convert_ctx = sws_getContext(pCodecCtx->width, pCodecCtx->height, pCodecCtx->pix_fmt, pCodecCtx->width, pCodecCtx->height,
//                                                                PIX_FMT_RGB24,
PIX_FMT_YUV420P, SWS_BICUBIC, NULL, NULL, NULL );

// Set SDL events
SDL_EventState(SDL_ACTIVEEVENT, SDL_IGNORE);
SDL_EventState(SDL_MOUSEMOTION, SDL_IGNORE);
SDL_ShowCursor(SDL_DISABLE);

// Read frames
while ((av_read_frame(pFormatCtx, &packet) >= 0) && (SDL_PollEvent(NULL ) == 0)) {
// Is this a packet from the video stream?
if (packet.stream_index == videoStream) {
// Decode video frame
avcodec_decode_video(pCodecCtx, pFrame, &frameFinished, packet.data, packet.size);
// Did we get a video frame?
if (frameFinished) {
// Convert the image from its native format to YUV, and display

SDL_LockYUVOverlay(overlay);
pFrameYUV->data[0] = overlay->pixels[0];
pFrameYUV->data[1] = overlay->pixels[2];
pFrameYUV->data[2] = overlay->pixels[1];

pFrameYUV->linesize[0] = overlay->pitches[0];
pFrameYUV->linesize[1] = overlay->pitches[2];
pFrameYUV->linesize[2] = overlay->pitches[1];

//                img_convert((AVPicture *) pFrameYUV, PIX_FMT_YUV420P, (AVPicture *) pFrame, pCodecCtx->pix_fmt, pCodecCtx->width,
//                        pCodecCtx->height);

// other codes
// Convert the image from its native format to RGB

sws_scale(img_convert_ctx, (const uint8_t* const *) pFrame->data, pFrame->linesize, 0, pCodecCtx->height, pFrameYUV->data,
pFrameYUV->linesize);

SDL_UnlockYUVOverlay(overlay);
SDL_DisplayYUVOverlay(overlay, &rect);
///
SDL_Delay(30);
}
}
// Free the packet that was allocated by av_read_frame
av_free_packet(&packet);
}
// Free the RGB image
av_free(pFrameYUV);
// Free the YUV frame
av_free(pFrame);
// Close the codec
avcodec_close(pCodecCtx);
// Close the video file
av_close_input_file(pFormatCtx);
//
SDL_FreeYUVOverlay(overlay);
return 0;
}

放大播放：

#include <SDL/SDL.h>

#include <libavcodec/avcodec.h>
#include <libavformat/avformat.h>
#include <stdio.h>
#include <libswscale/swscale.h>

int avcodec_main(int argc, char *argv[]) {
AVFormatContext *pFormatCtx;
int i, videoStream;
AVCodecContext *pCodecCtx;
AVCodec *pCodec;
AVFrame *pFrame;
AVFrame *pFrameYUV;
AVPacket packet;
int frameFinished;
int numBytes;

// Register all formats and codecs
av_register_all();
// Open video file
if (av_open_input_file(&pFormatCtx, "/home/user/workspace/panda/media/video/4f5a9c384d94eb21e5273ec263457535.mp4", NULL, 0, NULL )
!= 0) {
printf("===  cannot open file\n===");
return -1; // Couldn't open file
}
// Retrieve stream information
if (av_find_stream_info(pFormatCtx) < 0)
return -1; // Couldn't find stream information
// Dump information about file onto standard error
//	dump_format(pFormatCtx, 0, argv[1], false);
// Find the first video stream
videoStream = -1;
for (i = 0; i < pFormatCtx->nb_streams; i++)
if (pFormatCtx->streams[i]->codec->codec_type == CODEC_TYPE_VIDEO) ////////
{
videoStream = i;
break;
}
if (videoStream == -1)
return -1; // Didn't find a video stream
// Get a pointer to the codec context for the video stream
pCodecCtx = pFormatCtx->streams[videoStream]->codec; //////////

///////// SDL initialization
int w = 1920, h = 1080;

SDL_Surface *screen = SDL_SetVideoMode(w, h, 0, SDL_HWSURFACE);
SDL_Overlay *overlay = SDL_CreateYUVOverlay(w, h, SDL_YV12_OVERLAY, screen);
static SDL_Rect rect;
rect.x = 0;
rect.y = 0;
rect.w = w;
rect.h = h;
//////////
// Find the decoder for the video stream
pCodec = avcodec_find_decoder(pCodecCtx->codec_id);
if (pCodec == NULL )
return -1; // Codec not found
// Open codec
if (avcodec_open(pCodecCtx, pCodec) < 0)
return -1; // Could not open codec

// Allocate video frame
pFrame = avcodec_alloc_frame();
// Allocate an AVFrame structure
pFrameYUV = avcodec_alloc_frame();
if (pFrameYUV == NULL )
return -1;

static struct SwsContext *img_convert_ctx;

img_convert_ctx = sws_getContext(pCodecCtx->width, pCodecCtx->height, pCodecCtx->pix_fmt, w, h,
//				                                                PIX_FMT_RGB24,
PIX_FMT_YUV420P, SWS_BICUBIC, NULL, NULL, NULL );

// Set SDL events
SDL_EventState(SDL_ACTIVEEVENT, SDL_IGNORE);
SDL_EventState(SDL_MOUSEMOTION, SDL_IGNORE);
SDL_ShowCursor(SDL_DISABLE);

// Read frames
while ((av_read_frame(pFormatCtx, &packet) >= 0) && (SDL_PollEvent(NULL ) == 0)) {
// Is this a packet from the video stream?
if (packet.stream_index == videoStream) {
// Decode video frame
avcodec_decode_video(pCodecCtx, pFrame, &frameFinished, packet.data, packet.size);
// Did we get a video frame?
if (frameFinished) {
// Convert the image from its native format to YUV, and display

SDL_LockYUVOverlay(overlay);
pFrameYUV->data[0] = overlay->pixels[0];
pFrameYUV->data[1] = overlay->pixels[2];
pFrameYUV->data[2] = overlay->pixels[1];

pFrameYUV->linesize[0] = overlay->pitches[0];
pFrameYUV->linesize[1] = overlay->pitches[2];
pFrameYUV->linesize[2] = overlay->pitches[1];

//				img_convert((AVPicture *) pFrameYUV, PIX_FMT_YUV420P, (AVPicture *) pFrame, pCodecCtx->pix_fmt, pCodecCtx->width,
//						pCodecCtx->height);

// other codes
// Convert the image from its native format to RGB

sws_scale(img_convert_ctx, (const uint8_t* const *) pFrame->data, pFrame->linesize, 0, pCodecCtx->height, pFrameYUV->data,
pFrameYUV->linesize);

SDL_UnlockYUVOverlay(overlay);
SDL_DisplayYUVOverlay(overlay, &rect);
///
SDL_Delay(30);
}
}
// Free the packet that was allocated by av_read_frame
av_free_packet(&packet);
}
// Free the RGB image
av_free(pFrameYUV);
// Free the YUV frame
av_free(pFrame);
// Close the codec
avcodec_close(pCodecCtx);
// Close the video file
av_close_input_file(pFormatCtx);
//
SDL_FreeYUVOverlay(overlay);
return 0;
}

　　

参考http://hi.baidu.com/xiaomeng008/archive/tag/ffmpeg

ffmpeg： /article/1670641.html

ffmpeg编译和使用大全 http://lvzun.iteye.com/blog/706121

重点推荐：http://dranger.com/ffmpeg/ An ffmpeg and SDL Tutorial

http://www.libsdl.org/release/SDL-1.2.15/test/ SDL官方示例。 overlay有rgb转换到YUV.