you never do any read packets and decode after each av_seek_frame??? "seek" only moves the read pointer to the place you want, you must redo a whole processes of "av_read_frame", "avcodec_decode_video2", "swscale..." to get a new picture
On Feb 24, 3:15 am, cervello <[email protected]> wrote: > I have an array that keeps which frames are the keyframe and I want to > create a video with these keyframes but first off all I try to save > these keyframes in a directory in sdcard called "keyframes". > I use a video that I have 217 keyframe and I think I understand using > of av_seek_frame() wrong . > Because my code always save the last frame 217 times with different > names like frame1,frame2...frame217. > Can someone help me? Thank you. > > void SaveFrame(AVFrame *pFrame, int width, int height, int iFrame) { > log_message("saving frame."); > > FILE *pFile; > char szFilename[32]; > int y; > // Open file > sprintf(szFilename, "/sdcard/keyframes/frame%d.ppm", iFrame+1); > 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); > > } > > jint Java_com_test_Test_takePics(JNIEnv* env, jobject javaThis) { > > const char path[256] = "/sdcard/keyframes/"; > if (mkdir (path) != 0) printf("Fail Retry"); > > log_message("Fonka girdim!\n"); > > AVFormatContext *pFormatCtx; > int i, videoStream, j; > AVCodecContext *pCodecCtx; > AVCodec *pCodec; > AVFrame *pFrame; > AVFrame *pFrameRGB; > AVPacket packet; > int frameFinished; > int numBytes; > uint8_t *buffer; > unsigned char r, g, b; > int framecount; > > char* filename = "/sdcard/do-beer-not-drugs.3gp"; > // Register all formats and codecs > av_register_all(); > > // Open video file > if(av_open_input_file(&pFormatCtx, filename, NULL, 0, NULL)!=0) > 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, filename, 0); > > framecount = pFormatCtx->streams[0]->nb_frames; > hist = malloc(framecount*sizeof(int*)); > > for (j = 0; j < framecount; ++j) { > hist[j] = malloc(sizeof(int)*64); // this is because > we use 64-bin > histogram > } > for (i = 0; i < framecount; i++) { > for (j = 0; j < 64; j++) { > hist[i][j] = 0; > } > > } > > // 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; > > // 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 > > // 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; > > // 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); > > for (j = 0; j < > 3*pCodecCtx->height*pCodecCtx->width -3; j++) { > > r = (unsigned char) pFrameRGB->data[0][j]; > > g = (unsigned char) pFrameRGB->data[0][j > +1]; > > b = (unsigned char) pFrameRGB->data[0][j > +2]; > > > r = (unsigned char) ((r >> 2) & 0x30); > > g = (unsigned char) ((g >> 4) & 0x0C); > > b = (unsigned char) ((b >> 6) & 0x03); > > > unsigned char h = (unsigned char)(r|g|b); > > hist[i][h]++; > } > i++; > } > } > > // Free the packet that was allocated by av_read_frame > av_free_packet(&packet); > } > > framecount = i; > int keyframelength=select_keyFrames(framecount); > > for(i=1;i<keyframelength+1;i++){ > int64_t timeStamp = (int64_t)((pFormatCtx->duration) / > framecount)*keyFrames[i]/100; > av_seek_frame(pFormatCtx,0,timeStamp,AVSEEK_FLAG_ANY); > SaveFrame(pFrameRGB, pCodecCtx->width, pCodecCtx->height, i); > > } > > free(keyFrames); > // 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 > av_close_input_file(pFormatCtx); > > return 0; > > > > > > > > } -- You received this message because you are subscribed to the Google Groups "Android Developers" group. 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