[FFmpeg-devel] [PATCH] avformat/adxdec: demux multiple blocks at once

[Andreas Rheinhardt]

Paul B Mahol:
> Improves decoding speed by 24x
> 
> Signed-off-by: Paul B Mahol <onemda at gmail.com>
> ---
>  libavformat/adxdec.c | 23 +++++++++++++++--------
>  1 file changed, 15 insertions(+), 8 deletions(-)
> 
> diff --git a/libavformat/adxdec.c b/libavformat/adxdec.c
> index ccd5049acd..0e4c251cfc 100644
> --- a/libavformat/adxdec.c
> +++ b/libavformat/adxdec.c
> @@ -53,6 +53,9 @@ static int adx_read_packet(AVFormatContext *s, AVPacket *pkt)
>      AVCodecParameters *par = s->streams[0]->codecpar;
>      int ret, size;
>  
> +    if (avio_feof(s->pb))
> +        return AVERROR_EOF;
> +
>      if (par->channels <= 0) {
>          av_log(s, AV_LOG_ERROR, "invalid number of channels %d\n", par->channels);
>          return AVERROR_INVALIDDATA;
> @@ -63,16 +66,20 @@ static int adx_read_packet(AVFormatContext *s, AVPacket *pkt)
>      pkt->pos = avio_tell(s->pb);
>      pkt->stream_index = 0;
>  
> -    ret = av_get_packet(s->pb, pkt, size);
> -    if (ret != size) {
> -        return ret < 0 ? ret : AVERROR(EIO);
> -    }
> -    if (AV_RB16(pkt->data) & 0x8000) {
> -        return AVERROR_EOF;
> +    ret = av_get_packet(s->pb, pkt, size * 128);
> +    if (ret < 0)
> +        return ret;
> +    if ((ret % size) && ret >= size) {

So if ret < size you don't set the corrupt flag. Why?

> +        size = ret - (ret % size);
> +        av_shrink_packet(pkt, size);
> +        pkt->flags &= ~AV_PKT_FLAG_CORRUPT;
> +    } else {
> +        size = ret;
>      }
> +
>      pkt->size     = size;

This line makes no sense any more: If the first branch above is taken,
av_shrink_packet() will already set the size; in the other branch,
av_get_packet() already did.

> -    pkt->duration = 1;
> -    pkt->pts      = (pkt->pos - c->header_size) / size;
> +    pkt->duration = size / (BLOCK_SIZE * par->channels);
> +    pkt->pts      = (pkt->pos - c->header_size) / (BLOCK_SIZE * par->channels);
>  
>      return 0;
>  }
>