On 02/15/2014 11:28 AM, Tim Walker wrote:
> ---
> libavcodec/ac3dec.c | 32 ++++++++++++++++++++++++++++++++
> 1 file changed, 32 insertions(+)
>
> diff --git a/libavcodec/ac3dec.c b/libavcodec/ac3dec.c
> index fcb52e1..c1b0e8c 100644
> --- a/libavcodec/ac3dec.c
> +++ b/libavcodec/ac3dec.c
> @@ -31,6 +31,7 @@
>
> #include "libavutil/channel_layout.h"
> #include "libavutil/crc.h"
> +#include "libavutil/downmix_info.h"
> #include "libavutil/opt.h"
> #include "internal.h"
> #include "aac_ac3_parser.h"
> @@ -1308,6 +1309,7 @@ static int ac3_decode_frame(AVCodecContext * avctx,
> void *data,
> const uint8_t *channel_map;
> const float *output[AC3_MAX_CHANNELS];
> enum AVMatrixEncoding matrix_encoding;
> + AVDownmixInfo *downmix_info;
>
> /* copy input buffer to decoder context to avoid reading past the end
> of the buffer, which can be caused by a damaged input stream. */
> @@ -1478,6 +1480,36 @@ static int ac3_decode_frame(AVCodecContext * avctx,
> void *data,
> if ((ret = ff_side_data_update_matrix_encoding(frame, matrix_encoding))
> < 0)
> return ret;
>
> + /*
> + * AVDownmixInfo
> + *
> + * Note: LFE mix level (dB) = 10 - LFE mix level code
> + */
> + if ((downmix_info = av_downmix_info_update_side_data(frame))) {
The only way downmix_info can be NULL is on allocation failure, so I
would prefer that this return AVERROR(ENOMEM) instead of silently
returning successfully.
> + switch (s->preferred_downmix) {
> + case AC3_DMIXMOD_LTRT:
> + downmix_info->preferred_downmix_type = AV_DOWNMIX_TYPE_LTRT;
> + break;
> + case AC3_DMIXMOD_LORO:
> + downmix_info->preferred_downmix_type = AV_DOWNMIX_TYPE_LORO;
> + break;
> + case AC3_DMIXMOD_DPLII:
> + downmix_info->preferred_downmix_type = AV_DOWNMIX_TYPE_DPLII;
> + break;
> + default:
> + downmix_info->preferred_downmix_type = AV_DOWNMIX_TYPE_UNKNOWN;
> + break;
> + }
> + downmix_info->center_mix_level = gain_levels[s->
> center_mix_level];
> + downmix_info->center_mix_level_ltrt = gain_levels[s->
> center_mix_level_ltrt];
> + downmix_info->surround_mix_level = gain_levels[s->
> surround_mix_level];
> + downmix_info->surround_mix_level_ltrt =
> gain_levels[s->surround_mix_level_ltrt];
> + if (s->lfe_mix_level_exists)
> + downmix_info->lfe_mix_level = pow(10.0, (10 -
> s->lfe_mix_level) / 20.0);
> + else
> + downmix_info->lfe_mix_level = 0.0; // -inf dB
A table of lfe gain levels would be nice. Also you can remove the TODO
comment in eac3dec.c about using lfe mix level.
Thanks,
Justin
_______________________________________________
libav-devel mailing list
[email protected]
https://lists.libav.org/mailman/listinfo/libav-devel
