[FFmpeg-devel] [PATCH] recover from truncated aiff

[Baptiste Coudurier]

Hi,

Maksym Veremeyenko wrote:
> Maksym Veremeyenko ???????(??):
> [...]
>> Please have a look on attached patch.
> i was wrong in pkt->dts calculation, so have a look at attached patch.
> 
> 
> ------------------------------------------------------------------------
> 
> Index: libavformat/raw.c
> ===================================================================
> --- libavformat/raw.c	(revision 15899)
> +++ libavformat/raw.c	(working copy)
 >
> [...]
 >
> @@ -138,25 +142,29 @@
>  
>  static int raw_read_packet(AVFormatContext *s, AVPacket *pkt)
>  {
> -    int ret, size, bps;
> -    //    AVStream *st = s->streams[0];
> +    int ret;
> +    AVStream *st = s->streams[0];
>  
> -    size= RAW_PACKET_SIZE;
> +    /* End of stream may be reached */
> +    if (url_feof(s->pb))
> +        return AVERROR(EIO);
>  
> -    ret= av_get_packet(s->pb, pkt, size);
> +    /* Now for that packet */
> +    ret= av_get_packet(s->pb, pkt, (RAW_PACKET_SIZE / st->codec->block_align) * st->codec->block_align);

Michael suggested to use RAW_PACKET_SIZE*st->codec->block_align in case 
it was not clear, this way packets have the same duration, whatever 
channels or bps it is.

>      pkt->stream_index = 0;
>      if (ret <= 0) {
>          return AVERROR(EIO);
>      }
> -    /* note: we need to modify the packet size here to handle the last
> -       packet */
> -    pkt->size = ret;
>  
> -    bps= av_get_bits_per_sample(s->streams[0]->codec->codec_id);
> -    assert(bps); // if false there IS a bug elsewhere (NOT in this function)
> +    /* align packet on truncated file */
> +    if (0 != (ret % st->codec->block_align)) {
> +        pkt->size -= pkt->size % st->codec->block_align;
> +        av_log(s, AV_LOG_WARNING, "truncated packet detected, dropped %d bytes\n", ret - pkt->size);
> +    }

Humm, you do not set pkt->size before ?
Also use "if (ret % st->codec->block_align) {", more clear.

>      pkt->dts=
> -    pkt->pts= pkt->pos*8 / (bps * s->streams[0]->codec->channels);
> +    pkt->pts= pkt->pos / st->codec->block_align;

This is cosmetic and should be in a separate patch IMHO.

[...]

-- 
Baptiste COUDURIER                              GnuPG Key Id: 0x5C1ABAAA
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