[FFmpeg-devel] [PATCH] oggdec: Initialize stream index to -1 in ogg_packet.

[Alexander Strasser]

Hi Reimar,

Reimar Döffinger wrote:
> The previous method of having to initialize it outside lead
> to incorrect code: even if it was initialized, it usually was
> only initialized ones, thus a packet that could not be matched
  
  once

> to any stream would just be processed with the return values
> from the previous call.
> 
> Signed-off-by: Reimar Döffinger <Reimar.Doeffinger at gmx.de>
> ---
>  libavformat/oggdec.c |   12 +++++++++---
>  1 file changed, 9 insertions(+), 3 deletions(-)
> 
> diff --git a/libavformat/oggdec.c b/libavformat/oggdec.c
> index cb149ed..eb2e8b9 100644
> --- a/libavformat/oggdec.c
> +++ b/libavformat/oggdec.c
> @@ -337,6 +337,11 @@ static int ogg_read_page(AVFormatContext *s, int *str)
>      return 0;
>  }
>  
> +/**
> + * *str is set to -1 if there is no matching stream for the packet found,
> + * assume all other return values to be uninitialized in that case.
> + * Returns negative value on error or EOF.
> + */

  Could also have

  @brief Read an Ogg packet

  and

  @return ...

>  static int ogg_packet(AVFormatContext *s, int *str, int *dstart, int *dsize,
>                        int64_t *fpos)
>  {
> @@ -347,6 +352,8 @@ static int ogg_packet(AVFormatContext *s, int *str, int *dstart, int *dsize,
>      int segp = 0, psize = 0;
>  
>      av_dlog(s, "ogg_packet: curidx=%i\n", ogg->curidx);
> +    if (str)
> +        *str = -1;
>  
>      do{
>          idx = ogg->curidx;
> @@ -525,7 +532,6 @@ static int ogg_get_length(AVFormatContext *s)
>      ogg_save (s);
>      avio_seek (s->pb, s->data_offset, SEEK_SET);
>      ogg_reset(s);
> -    i = -1;
>      while (streams_left > 0 && !ogg_packet(s, &i, NULL, NULL, NULL)) {
>          int64_t pts;
>          if (i < 0) continue;
> @@ -612,7 +618,7 @@ static int ogg_read_packet(AVFormatContext *s, AVPacket *pkt)
>  {
>      struct ogg *ogg;
>      struct ogg_stream *os;
> -    int idx = -1, ret;
> +    int idx, ret;
>      int pstart, psize;
>      int64_t fpos, pts, dts;
>  
> @@ -671,7 +677,7 @@ static int64_t ogg_read_timestamp(AVFormatContext *s, int stream_index,
>      AVIOContext *bc = s->pb;
>      int64_t pts = AV_NOPTS_VALUE;
>      int64_t keypos = -1;
> -    int i = -1;
> +    int i;
>      int pstart, psize;
>      avio_seek(bc, *pos_arg, SEEK_SET);
>      ogg_reset(s);
> -- 
> 1.7.10.4

  These and the changes in the preceding patch LGTM.

  Alexander