[FFmpeg-trac] #576(swscale:new): sws_scale crash with PIX_FMT_YUVJ420P -> PIX_FMT_RGB24

[FFmpeg]

#576: sws_scale crash with PIX_FMT_YUVJ420P -> PIX_FMT_RGB24
------------------------------------+-----------------------------------
             Reporter:  rich99      |                    Owner:  michael
                 Type:  defect      |                   Status:  new
             Priority:  normal      |                Component:  swscale
              Version:  git-master  |               Resolution:
             Keywords:              |               Blocked By:
             Blocking:              |  Reproduced by developer:  0
Analyzed by developer:  0           |
------------------------------------+-----------------------------------

Comment (by rich99):

 Just to make sure, this is the final code, also attached as cpp.
 {{{

 #define __STDC_CONSTANT_MACROS

 extern "C"
 {
 #include <libavformat/avformat.h>
 #include <libswscale/swscale.h>
 #include <libavcodec/avcodec.h>
 #include <libavutil/opt.h>
 }

 int main(int argc, char *argv[])
 {
         av_register_all();

         AVFormatContext* pFormatCtx;
         if (argc == 2)
         {
                 av_open_input_file(&pFormatCtx, argv[1], NULL, 0, NULL);
         }
         else
         {
                 printf("need filename\n");

                 return -1;
         }

         av_find_stream_info(pFormatCtx);
         dump_format(pFormatCtx, 0, "test", 0);

         AVCodecContext* pCodecCtx;

         // i know first stream is at index 0, simplified here
         unsigned int videoStream = 0;
         pCodecCtx = pFormatCtx->streams[videoStream]->codec;

         AVCodec* pCodec = avcodec_find_decoder(pCodecCtx->codec_id);
         avcodec_open(pCodecCtx, pCodec);

         AVFrame* pFrame = avcodec_alloc_frame();
         AVFrame* pFrameRGB = avcodec_alloc_frame();

         PixelFormat destFormat = PIX_FMT_YUV420P;

         // Determine required buffer size and allocate buffer
         int numBytes = avpicture_get_size(destFormat, pCodecCtx->width,
 pCodecCtx->height);
         uint8_t* buffer = (uint8_t *)av_malloc(numBytes*sizeof(uint8_t));
         avpicture_fill((AVPicture *)pFrameRGB, buffer, destFormat,
 pCodecCtx->width, pCodecCtx->height);

         int frameFinished;
         AVPacket packet;

         SwsContext* swsContext = sws_alloc_context();
         //AVOption options;
         av_opt_set_defaults(swsContext);
         av_set_int(swsContext, "sws_flags", SWS_POINT);
         av_set_int(swsContext, "srcw", pCodecCtx->width);
         av_set_int(swsContext, "srch", pCodecCtx->height);
         av_set_int(swsContext, "dstw", pCodecCtx->width);
         av_set_int(swsContext, "dsth", pCodecCtx->height);
         av_set_int(swsContext, "src_format", pCodecCtx->pix_fmt);
         av_set_int(swsContext, "dst_format", destFormat);
         av_set_int(swsContext, "src_range", 1);
         av_set_int(swsContext, "dst_range", 1);

         sws_init_context(swsContext, NULL, NULL); //success

         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)
                         {
                                         AVPicture &pic =
 *(AVPicture*)pFrame;
                                         AVPicture &picDst =
 *(AVPicture*)pFrameRGB;
                                         // [CRASH HERE]
                                         sws_scale(swsContext,
 &pic.data[0], &pic.linesize[0], 0, pCodecCtx->height, &picDst.data[0],
 &picDst.linesize[0]);
                                         //
                                         printf(".");
                         }
                 }

                 // Free the packet that was allocated by av_read_frame
                 av_free_packet(&packet);
         }

         av_free(buffer);
         av_free(pFrameRGB);
         av_free(pFrame);
         sws_freeContext(swsContext);
         avcodec_close(pCodecCtx);
         av_close_input_file(pFormatCtx);

         return 0;
 }
 }}}

-- 
Ticket URL: <https://ffmpeg.org/trac/ffmpeg/ticket/576#comment:6>
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