[Ffmpeg-devel] [PATCH] ASF Stream bitrate GUID parsing....

[Michael Niedermayer]

Hi

On Thu, Jan 04, 2007 at 04:45:22PM -0600, Ryan Martell wrote:
> Hi--
> 
> To support my native mms code, I need to parse the bitrate GUID  
> header of the ASF file if it's present.  This small patch adds that  
> information to the ASFContext.
> 
> A couple of quick notes:
> 
> 1) The indentation is actually correct now (the block below is  
> indented incorrectly) on the lines:
> -       } else if (!memcmp(&g, &extended_content_header, sizeof 
> (GUID))) {
> +        } else if (!memcmp(&g, &stream_bitrate_guid, sizeof(GUID))) {
> 
> 2) I removed:
>  ASFStream streams[128];     /* it's max number and it's not that  
> big */
> >from the ASFContext, as it was unused (and big).  I replaced it with  
> a 128 uint32_t array, which seems fair.
[...]
> +        } else if (!memcmp(&g, &stream_bitrate_guid, sizeof(GUID))) {
> +            uint16_t streams = get_le16(pb);
> +            int j;
> +
> +#ifdef DEBUG
> +            av_log(NULL, AV_LOG_ERROR, "stream bitrate properties\n");
> +            av_log(NULL, AV_LOG_ERROR, "streams %d\n", streams);
> +#endif
> +
> +            for(j = 0; j < streams; j++) {
> +                uint16_t flags;
> +                uint32_t bitrate;
> +                int stream_id;
> +
> +                flags= get_le16(pb);
> +                bitrate= get_le32(pb);
> +                stream_id= (flags & 0x7f);
> +#ifdef DEBUG
> +                av_log(NULL, AV_LOG_ERROR, "flags: 0x%x stream id %d, bitrate %d\n", flags, stream_id, bitrate);
> +#endif
> +                asf->stream_bitrates[stream_id-1]= bitrate;

the -1 causes a possible write prior to the array


[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

While the State exists there can be no freedom; when there is freedom there
will be no State. -- Vladimir Lenin
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