When I use mpeg4 or h264 encoders, I can successfully encode images to make a valid AVI file using the API for ffmpeg 3.1.0. However, when I use Encoder Quick Sync (h264_qsv), avcodec_encode_video2 will freeze for a while. I found that when using images with a resolution of 1920x1080, avcodec_encode_video2 would rarely depend. When using 256x256 images, it is very likely that the function freezes.
I created the test code below which demonstrates the avcodec_encode_video2 hang. The code will create 1000 frames, 256x256 AVI with a bit rate of 400,000. The frames are just highlighted, so the output video should only be green frames.
The problem was observed using Windows 7 and Windows 10 using a 32-bit or 64-bit test application.
If anyone knows how I can avoid avcodec_encode_video2, I would be very grateful! Thanks in advance for any help.
extern "C" { #ifndef __STDC_CONSTANT_MACROS #define __STDC_CONSTANT_MACROS #endif #include "avcodec.h" #include "avformat.h" #include "swscale.h" #include "avutil.h" #include "imgutils.h" #include "opt.h" #include <rational.h> } #include <iostream> // Globals AVCodec* m_pCodec = NULL; AVStream *m_pStream = NULL; AVOutputFormat* m_pFormat = NULL; AVFormatContext* m_pFormatContext = NULL; AVCodecContext* m_pCodecContext = NULL; AVFrame* m_pFrame = NULL; int m_frameIndex; // Output format AVPixelFormat m_pixType = AV_PIX_FMT_NV12; // Use for mpeg4 //AVPixelFormat m_pixType = AV_PIX_FMT_YUV420P; // Output frame rate int m_frameRate = 30; // Output image dimensions int m_imageWidth = 256; int m_imageHeight = 256; // Number of frames to export int m_frameCount = 1000; // Output file name const char* m_fileName = "c:/test/test.avi"; // Output file type const char* m_fileType = "AVI"; // Codec name used to encode const char* m_encoderName = "h264_qsv"; // use for mpeg4 //const char* m_encoderName = "mpeg4"; // Target bit rate int m_targetBitRate = 400000; void addVideoStream() { m_pStream = avformat_new_stream( m_pFormatContext, m_pCodec ); m_pStream->id = m_pFormatContext->nb_streams - 1; m_pStream->time_base = m_pCodecContext->time_base; m_pStream->codec->pix_fmt = m_pixType; m_pStream->codec->flags = m_pCodecContext->flags; m_pStream->codec->width = m_pCodecContext->width; m_pStream->codec->height = m_pCodecContext->height; m_pStream->codec->time_base = m_pCodecContext->time_base; m_pStream->codec->bit_rate = m_pCodecContext->bit_rate; } AVFrame* allocatePicture( enum AVPixelFormat pix_fmt, int width, int height ) { AVFrame *frame; frame = av_frame_alloc(); if ( !frame ) { return NULL; } frame->format = pix_fmt; frame->width = width; frame->height = height; int checkImage = av_image_alloc( frame->data, frame->linesize, width, height, pix_fmt, 32 ); if ( checkImage < 0 ) { return NULL; } return frame; } bool initialize() { AVRational frameRate; frameRate.den = m_frameRate; frameRate.num = 1; av_register_all(); m_pCodec = avcodec_find_encoder_by_name(m_encoderName); if( !m_pCodec ) { return false; } m_pCodecContext = avcodec_alloc_context3( m_pCodec ); m_pCodecContext->width = m_imageWidth; m_pCodecContext->height = m_imageHeight; m_pCodecContext->time_base = frameRate; m_pCodecContext->gop_size = 0; m_pCodecContext->pix_fmt = m_pixType; m_pCodecContext->codec_id = m_pCodec->id; m_pCodecContext->bit_rate = m_targetBitRate; av_opt_set( m_pCodecContext->priv_data, "+CBR", "", 0 ); return true; } bool startExport() { m_frameIndex = 0; char fakeFileName[512]; int checkAllocContext = avformat_alloc_output_context2( &m_pFormatContext, NULL, m_fileType, fakeFileName ); if ( checkAllocContext < 0 ) { return false; } if ( !m_pFormatContext ) { return false; } m_pFormat = m_pFormatContext->oformat; if ( m_pFormat->video_codec != AV_CODEC_ID_NONE ) { addVideoStream(); int checkOpen = avcodec_open2( m_pCodecContext, m_pCodec, NULL ); if ( checkOpen < 0 ) { return false; } m_pFrame = allocatePicture( m_pCodecContext->pix_fmt, m_pCodecContext->width, m_pCodecContext->height ); if( !m_pFrame ) { return false; } m_pFrame->pts = 0; } int checkOpen = avio_open( &m_pFormatContext->pb, m_fileName, AVIO_FLAG_WRITE ); if ( checkOpen < 0 ) { return false; } av_dict_set( &(m_pFormatContext->metadata), "title", "QS Test", 0 ); int checkHeader = avformat_write_header( m_pFormatContext, NULL ); if ( checkHeader < 0 ) { return false; } return true; } int processFrame( AVPacket& avPacket ) { avPacket.stream_index = 0; avPacket.pts = av_rescale_q( m_pFrame->pts, m_pStream->codec->time_base, m_pStream->time_base ); avPacket.dts = av_rescale_q( m_pFrame->pts, m_pStream->codec->time_base, m_pStream->time_base ); m_pFrame->pts++; int retVal = av_interleaved_write_frame( m_pFormatContext, &avPacket ); return retVal; } bool exportFrame() { int success = 1; int result = 0; AVPacket avPacket; av_init_packet( &avPacket ); avPacket.data = NULL; avPacket.size = 0; fflush(stdout); std::cout << "Before avcodec_encode_video2 for frame: " << m_frameIndex << std::endl; success = avcodec_encode_video2( m_pCodecContext, &avPacket, m_pFrame, &result ); std::cout << "After avcodec_encode_video2 for frame: " << m_frameIndex << std::endl; if( result ) { success = processFrame( avPacket ); } av_packet_unref( &avPacket ); m_frameIndex++; return ( success == 0 ); } void endExport() { int result = 0; int success = 0; if (m_pFrame) { while ( success == 0 ) { AVPacket avPacket; av_init_packet( &avPacket ); avPacket.data = NULL; avPacket.size = 0; fflush(stdout); success = avcodec_encode_video2( m_pCodecContext, &avPacket, NULL, &result ); if( result ) { success = processFrame( avPacket ); } av_packet_unref( &avPacket ); if (!result) { break; } } } if (m_pFormatContext) { av_write_trailer( m_pFormatContext ); if( m_pFrame ) { av_frame_free( &m_pFrame ); } avio_closep( &m_pFormatContext->pb ); avformat_free_context( m_pFormatContext ); m_pFormatContext = NULL; } } void cleanup() { if( m_pFrame || m_pCodecContext ) { if( m_pFrame ) { av_frame_free( &m_pFrame ); } if( m_pCodecContext ) { avcodec_close( m_pCodecContext ); av_free( m_pCodecContext ); } } } int main() { bool success = true; if (initialize()) { if (startExport()) { for (int loop = 0; loop < m_frameCount; loop++) { if (!exportFrame()) { std::cout << "Failed to export frame\n"; success = false; break; } } endExport(); } else { std::cout << "Failed to start export\n"; success = false; } cleanup(); } else { std::cout << "Failed to initialize export\n"; success = false; } if (success) { std::cout << "Successfully exported file\n"; } return 1; }