[FFmpeg-devel] [PATCH V1] lavf/flvenc: add automatic bitstream filtering

[Steven Liu]

> 在 2019年6月22日，17:04，Jun Zhao <mypopydev at gmail.com> 写道：
> 
> From: Jun Zhao <barryjzhao at tencent.com>
> 
> add automatic bitstream filtering when mux AAC
> 
> Signed-off-by: Jun Zhao <barryjzhao at tencent.com>
> ---
> libavformat/flvenc.c |   27 ++++++++++++++++++++++++---
> 1 files changed, 24 insertions(+), 3 deletions(-)
> 
> diff --git a/libavformat/flvenc.c b/libavformat/flvenc.c
> index e4863f1..fb1dede 100644
> --- a/libavformat/flvenc.c
> +++ b/libavformat/flvenc.c
> @@ -653,11 +653,9 @@ end:
>     return ret;
> }
> 
> -
> -static int flv_write_header(AVFormatContext *s)
> +static int flv_init(struct AVFormatContext *s)
> {
>     int i;
> -    AVIOContext *pb = s->pb;
>     FLVContext *flv = s->priv_data;
> 
>     for (i = 0; i < s->nb_streams; i++) {
> @@ -736,6 +734,15 @@ static int flv_write_header(AVFormatContext *s)
> 
>     flv->delay = AV_NOPTS_VALUE;
> 
> +    return 0;
> +}
> +
> +static int flv_write_header(AVFormatContext *s)
> +{
> +    int i;
> +    AVIOContext *pb = s->pb;
> +    FLVContext *flv = s->priv_data;
> +
>     avio_write(pb, "FLV", 3);
>     avio_w8(pb, 1);
>     avio_w8(pb, FLV_HEADER_FLAG_HASAUDIO * !!flv->audio_par +
> @@ -1074,6 +1081,18 @@ static int flv_write_packet(AVFormatContext *s, AVPacket *pkt)
>     return pb->error;
> }
> 
> +static int flv_check_bitstream(struct AVFormatContext *s, const AVPacket *pkt)
> +{
> +    int ret = 1;
> +    AVStream *st = s->streams[pkt->stream_index];
> +
> +    if (st->codecpar->codec_id == AV_CODEC_ID_AAC) {
> +        if (pkt->size > 2 && (AV_RB16(pkt->data) & 0xfff0) == 0xfff0)
> +            ret = ff_stream_add_bitstream_filter(st, "aac_adtstoasc", NULL);
> +    }
> +    return ret;
> +}
> +
> static const AVOption options[] = {
>     { "flvflags", "FLV muxer flags", offsetof(FLVContext, flags), AV_OPT_TYPE_FLAGS, {.i64 = 0}, INT_MIN, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM, "flvflags" },
>     { "aac_seq_header_detect", "Put AAC sequence header based on stream data", 0, AV_OPT_TYPE_CONST, {.i64 = FLV_AAC_SEQ_HEADER_DETECT}, INT_MIN, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM, "flvflags" },
> @@ -1099,9 +1118,11 @@ AVOutputFormat ff_flv_muxer = {
>     .priv_data_size = sizeof(FLVContext),
>     .audio_codec    = CONFIG_LIBMP3LAME ? AV_CODEC_ID_MP3 : AV_CODEC_ID_ADPCM_SWF,
>     .video_codec    = AV_CODEC_ID_FLV1,
> +    .init           = flv_init,
>     .write_header   = flv_write_header,
>     .write_packet   = flv_write_packet,
>     .write_trailer  = flv_write_trailer,
> +    .check_bitstream= flv_check_bitstream,
>     .codec_tag      = (const AVCodecTag* const []) {
>                           flv_video_codec_ids, flv_audio_codec_ids, 0
>                       },
> -- 
> 1.7.1
> 
> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel at ffmpeg.org
> https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
> 
> To unsubscribe, visit link above, or email
> ffmpeg-devel-request at ffmpeg.org with subject "unsubscribe”.

LGTM

Don’t forget add add Reported-by: Yabo Wei

Thanks
Steven