[FFmpeg-devel] [PATCH v5] Add SUP/PGS subtitle demuxer

Carl Eugen Hoyos cehoyos at ag.or.at
Mon Sep 1 10:34:52 CEST 2014


wm4 <nfxjfg <at> googlemail.com> writes:

> +    avio_rb32(s->pb); /* discard DTS (usually 0, and useless) */

Would it be an option to set it dts to AV_NOPTS_VALUE 
if this value is 0 but use the value otherwise?
Or is there no advantage?

> +        full_packet_size = AV_RB16(buf + 10 + 1) + 10 + 3;
> +        if (buf_size < full_packet_size)
> +            break;

I don't know if it is worth the effort, but you could 
check for the first byte as well:
if (buf[10] != 0x80 || (buf[10] | 3) != 17)
    break;
With this change, you could increase the scores, reduce 
the number of maximum packets in the loop and maybe 
speed up probing iiuc.

> +    if (nb_packets < 4)
> +        return AVPROBE_SCORE_RETRY;

If you find three consecutive packets on the 
start of the file, at least EXTENSION is 
appropriate imo even without checking the 
content, possibly more.

Carl Eugen



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