Shulou(Shulou.com)06/03 Report--

Describe the FFmpeg3.4 version

Bool SaveYUV420ToJPEG (const std::string & strFileName, int nWidth, int nHeight, int linesize, uint8_t * Y, uint8_t * U, uint8_t * V)

{

AVFormatContext* pFormatCtx

AVCodecContext* pCodecCtx

AVCodec* pCodec

AVFrame* pFrame

AVPacket pkt

Int nRet = 0

Avformat_alloc_output_context2 (& pFormatCtx, NULL, NULL, strFileName.c_str ())

AVStream* pVideoAVStream = avformat_new_stream (pFormatCtx, 0)

If (NULL = = pVideoAVStream) return false

PCodecCtx = avcodec_alloc_context3 (NULL)

If (NULL = = pCodecCtx) return false

Avcodec_parameters_to_context (pCodecCtx, pVideoAVStream- > codecpar)

PCodecCtx- > codec_id = pFormatCtx- > oformat- > video_codec

PCodecCtx- > codec_type = AVMEDIA_TYPE_VIDEO

PCodecCtx- > pix_fmt = AV_PIX_FMT_YUVJ420P

PCodecCtx- > width = nWidth

PCodecCtx- > height = nHeight

PCodecCtx- > time_base.num = 1

PCodecCtx- > time_base.den = 25

PCodec = avcodec_find_encoder (pCodecCtx- > codec_id)

If (NULL = = pCodec) return false

If (avcodec_open2 (pCodecCtx, pCodec,NULL)

Qcompress = (float) nJpegQuality/100.f; / / 0. 0, default is 0. 5

PCodecCtx- > qmin = 2

PCodecCtx- > qmax = 31

PCodecCtx- > max_qdiff = 3

Avformat_write_header (pFormatCtx,NULL)

Av_new_packet (& pkt, pCodecCtx- > width * pCodecCtx- > height * 3)

PFrame- > data [0] = Y

PFrame- > data [1] = U

PFrame- > data [2] = V

PFrame- > linesize [0] = linesize

PFrame- > linesize [1] = linesize/2

PFrame- > linesize [2] = linesize/2

NRet = avcodec_send_frame (pCodecCtx, pFrame)

If (avcodec_receive_packet (pCodecCtx, & pkt)! = 0) return false

Pkt.stream_index = 0

NRet = av_write_frame (pFormatCtx, & pkt)

Av_packet_unref & pkt)

Av_write_trailer (pFormatCtx)

Avcodec_close (pCodecCtx)

Avcodec_free_context & pCodecCtx)

Av_frame_free & pFrame)

Avio_close (pFormatCtx- > pb)

Avformat_free_context (pFormatCtx)

Return true

}

Call example

SaveYUV420ToJPEG ("fengyuzaitu.jpg", pFrame- > width, pFrame- > height, pFrame- > linesize [0], pFrame- > data [0], pFrame- > data [1], pFrame- > data [2])

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.