diff options
Diffstat (limited to 'src/test-native/ffmpeg/avcodec_sample.c')
| -rw-r--r-- | src/test-native/ffmpeg/avcodec_sample.c | 203 |
1 files changed, 203 insertions, 0 deletions
diff --git a/src/test-native/ffmpeg/avcodec_sample.c b/src/test-native/ffmpeg/avcodec_sample.c new file mode 100644 index 000000000..f4001b4e6 --- /dev/null +++ b/src/test-native/ffmpeg/avcodec_sample.c @@ -0,0 +1,203 @@ +// avcodec_sample.0.5.0.c + +// A small sample program that shows how to use libavformat and libavcodec to +// read video from a file. +// +// This version is for the 0.4.9+ release of ffmpeg. This release adds the +// av_read_frame() API call, which simplifies the reading of video frames +// considerably. +// +// Use +// +// gcc -o avcodec_sample.0.5.0 avcodec_sample.0.5.0.c -lavformat -lavcodec -lavutil -lswscale -lz -lbz2 +// +// to build (assuming libavformat, libavcodec, libavutil, and swscale are correctly installed on +// your system). +// +// Run using +// +// avcodec_sample.0.5.0 myvideofile.mpg +// +// to write the first five frames from "myvideofile.mpg" to disk in PPM +// format. + +#include <libavcodec/avcodec.h> +#include <libavformat/avformat.h> +#include <libswscale/swscale.h> + +#include <stdio.h> +#include <stdlib.h> +#include <stdbool.h> + +static void SaveFrame(AVFrame *pFrame, int width, int height, int iFrame); + +int main (int argc, const char * argv[]) +{ + AVFormatContext *pFormatCtx; + int i, videoStream; + AVCodecContext *pCodecCtx; + AVCodec *pCodec; + AVFrame *pFrame; + AVFrame *pFrameRGB; + AVPacket packet; + int frameFinished; + int numBytes; + uint8_t *buffer; + + // Register all formats and codecs + av_register_all(); + + avformat_network_init(); + + // Open video file + if(avformat_open_input(&pFormatCtx, argv[1], NULL, NULL)!=0) + return -1; // Couldn't open file + + // Retrieve stream information + if(avformat_find_stream_info(pFormatCtx, NULL)<0) + return -1; // Couldn't find stream information + + // Dump information about file onto standard error + av_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==AVMEDIA_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; + + // 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_open2(pCodecCtx, pCodec, NULL)<0) + return -1; // Could not open codec + + // Hack to correct wrong frame rates that seem to be generated by some codecs + if(pCodecCtx->time_base.num>1000 && pCodecCtx->time_base.den==1) + pCodecCtx->time_base.den=1000; + + // Allocate video frame + pFrame=avcodec_alloc_frame(); + + // Allocate an AVFrame structure + pFrameRGB=avcodec_alloc_frame(); + if(pFrameRGB==NULL) + return -1; + + // Determine required buffer size and allocate buffer + numBytes=avpicture_get_size(PIX_FMT_RGB24, pCodecCtx->width, + pCodecCtx->height); + + buffer=malloc(numBytes); + + // Assign appropriate parts of buffer to image planes in pFrameRGB + avpicture_fill((AVPicture *)pFrameRGB, buffer, PIX_FMT_RGB24, + pCodecCtx->width, pCodecCtx->height); + + // Read frames and save first five frames to disk + i=0; + while(av_read_frame(pFormatCtx, &packet)>=0) + { + // Is this a packet from the video stream? + if(packet.stream_index==videoStream) + { + // Decode video frame + avcodec_decode_video2(pCodecCtx, pFrame, &frameFinished, &packet); + + // Did we get a video frame? + if(frameFinished) + { + static struct SwsContext *img_convert_ctx; + +#if 0 + // Older removed code + // Convert the image from its native format to RGB swscale + img_convert((AVPicture *)pFrameRGB, PIX_FMT_RGB24, + (AVPicture*)pFrame, pCodecCtx->pix_fmt, pCodecCtx->width, + pCodecCtx->height); + + // function template, for reference + int sws_scale(struct SwsContext *context, uint8_t* src[], int srcStride[], int srcSliceY, + int srcSliceH, uint8_t* dst[], int dstStride[]); +#endif + // Convert the image into YUV format that SDL uses + if(img_convert_ctx == NULL) { + int w = pCodecCtx->width; + int h = pCodecCtx->height; + + img_convert_ctx = sws_getContext(w, h, + pCodecCtx->pix_fmt, + w, h, PIX_FMT_RGB24, SWS_BICUBIC, + NULL, NULL, NULL); + if(img_convert_ctx == NULL) { + fprintf(stderr, "Cannot initialize the conversion context!\n"); + exit(1); + } + } + int ret = sws_scale(img_convert_ctx, pFrame->data, pFrame->linesize, 0, + pCodecCtx->height, pFrameRGB->data, pFrameRGB->linesize); +#if 0 // this use to be true, as of 1/2009, but apparently it is no longer true in 3/2009 + if(ret) { + fprintf(stderr, "SWS_Scale failed [%d]!\n", ret); + exit(-1); + } +#endif + // Save the frame to disk + if(i++<=5) + SaveFrame(pFrameRGB, pCodecCtx->width, pCodecCtx->height, i); + } + } + + // Free the packet that was allocated by av_read_frame + av_free_packet(&packet); + } + + // Free the RGB image + free(buffer); + av_free(pFrameRGB); + + // Free the YUV frame + av_free(pFrame); + + // Close the codec + avcodec_close(pCodecCtx); + + // Close the video file + avformat_close_input(&pFormatCtx); + + return 0; +} + +static void SaveFrame(AVFrame *pFrame, int width, int height, int iFrame) +{ + FILE *pFile; + char szFilename[32]; + int y; + + // Open file + sprintf(szFilename, "frame%d.ppm", iFrame); + pFile=fopen(szFilename, "wb"); + if(pFile==NULL) + return; + + // Write header + fprintf(pFile, "P6\n%d %d\n255\n", width, height); + + // Write pixel data + for(y=0; y<height; y++) + fwrite(pFrame->data[0]+y*pFrame->linesize[0], 1, width*3, pFile); + + // Close file + fclose(pFile); +} |