[FFmpeg-devel] [PATCH] extend ac3 parser to fetch more values

[Justin Ruggles]

Baptiste Coudurier wrote:
> Hi
> 
> $subject, these fields are needed to be put in extradata in mp4, don't
> ask me why see with ETSI :(
> 
> 
> Index: libavcodec/ac3_parser.c
> ===================================================================
> --- libavcodec/ac3_parser.c	(revision 15046)
> +++ libavcodec/ac3_parser.c	(working copy)
> @@ -62,13 +62,13 @@
>          if(hdr->sr_code == 3)
>              return AC3_PARSE_ERROR_SAMPLE_RATE;
>  
> -        frame_size_code = get_bits(gbc, 6);
> -        if(frame_size_code > 37)
> +        hdr->frame_size_code = get_bits(gbc, 6);
> +        if(hdr->frame_size_code > 37)
>              return AC3_PARSE_ERROR_FRAME_SIZE;
>  
>          skip_bits(gbc, 5); // skip bsid, already got it
>  
> -        skip_bits(gbc, 3); // skip bitstream mode
> +        hdr->bitstream_mode = get_bits(gbc, 3);
>          hdr->channel_mode = get_bits(gbc, 3);
>  
>          if(hdr->channel_mode == AC3_CHMODE_STEREO) {
> @@ -83,9 +83,9 @@
>  
>          hdr->sr_shift = FFMAX(hdr->bitstream_id, 8) - 8;
>          hdr->sample_rate = ff_ac3_sample_rate_tab[hdr->sr_code] >> hdr->sr_shift;
> -        hdr->bit_rate = (ff_ac3_bitrate_tab[frame_size_code>>1] * 1000) >> hdr->sr_shift;
> +        hdr->bit_rate = (ff_ac3_bitrate_tab[hdr->frame_size_code>>1] * 1000) >> hdr->sr_shift;
>          hdr->channels = ff_ac3_channels_tab[hdr->channel_mode] + hdr->lfe_on;
> -        hdr->frame_size = ff_ac3_frame_size_tab[frame_size_code][hdr->sr_code] * 2;
> +        hdr->frame_size = ff_ac3_frame_size_tab[hdr->frame_size_code][hdr->sr_code] * 2;
>          hdr->frame_type = EAC3_FRAME_TYPE_AC3_CONVERT; //EAC3_FRAME_TYPE_INDEPENDENT;
>          hdr->substreamid = 0;
>      } else {
> Index: libavcodec/ac3.h
> ===================================================================
> --- libavcodec/ac3.h	(revision 15046)
> +++ libavcodec/ac3.h	(working copy)
> @@ -81,7 +81,9 @@
>      uint16_t sync_word;
>      uint16_t crc1;
>      uint8_t sr_code;
> +    uint8_t frame_size_code;
>      uint8_t bitstream_id;
> +    uint8_t bitstream_mode;
>      uint8_t channel_mode;
>      uint8_t lfe_on;
>      uint8_t frame_type;

patch ok.

-Justin