Ticket #576: ffdmjpeg.cpp

#define __STDC_CONSTANT_MACROS
#pragma warning(disable:4244)

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;
}