ffmpeg-encode.cpp

ffmpeg encode

// Snippet from https://stackoverflow.com/questions/16252905/why-do-i-get-a-crash-only-sometimes-when-closing-input-file-with-ffmpeg
// save the frame to file
                int Bytes = avpicture_get_size(PIX_FMT_YUVJ420P, CodecCtx->width, CodecCtx->height);
                BufferHandle buffer((uint8_t*)av_malloc(Bytes*sizeof(uint8_t)), av_free);
                CodecContextHandle OutContext(avcodec_alloc_context3(NULL), free_context);
                OutContext->bit_rate = CodecCtx->bit_rate;
                OutContext->width = CodecCtx->width;
                OutContext->height = CodecCtx->height;
                OutContext->pix_fmt = PIX_FMT_YUVJ420P;
                OutContext->codec_id = CODEC_ID_MJPEG;
                OutContext->codec_type = AVMEDIA_TYPE_VIDEO;
                OutContext->time_base.num = CodecCtx->time_base.num;
                OutContext->time_base.den = CodecCtx->time_base.den;
                AVCodec *OutCodec = avcodec_find_encoder(OutContext->codec_id);
                avcodec_open2(OutContext, OutCodec, NULL);
                OutContext->mb_lmin = OutContext->lmin = OutContext->qmin * 118;
                OutContext->mb_lmax = OutContext->lmax = OutContext->qmax * 118;
                OutContext->flags = 2;
                OutContext->global_quality = OutContext->qmin * 118;

                Frame->pts = 1;
                Frame->quality = OutContext->global_quality;

                int ActualSize = avcodec_encode_video(OutContext, buffer, Bytes, Frame);
                std::ofstream file("c:\\temp\\output.jpg", std::ios_base::binary | std::ios_base::out);
                file.write((const char*)(uint8_t*)buffer, ActualSize);