On 09/18/2012 09:02 PM, Nathan Caldwell wrote:
> This way we can directly remap channels from Opus' channel order to libav's
> internal channel order.
> Instead of mapping channels from Opus' order to Vorbis' order then to libav's
> order.
> ---
> libavcodec/libopusdec.c | 37 ++++++++++++-------------------------
> 1 file changed, 12 insertions(+), 25 deletions(-)
>
> diff --git a/libavcodec/libopusdec.c b/libavcodec/libopusdec.c
> index b13b6ea..33df01b 100644
> --- a/libavcodec/libopusdec.c
> +++ b/libavcodec/libopusdec.c
> @@ -35,28 +35,13 @@ struct libopus_context {
> int pre_skip;
> };
>
> -static inline void reorder(uint8_t *data, unsigned channels, unsigned bps,
> - unsigned samples, const uint8_t *map)
> -{
> - uint8_t tmp[8 * 4];
> - unsigned i;
> -
> - av_assert1(channels * bps <= sizeof(tmp));
> - for (; samples > 0; samples--) {
> - for (i = 0; i < channels; i++)
> - memcpy(tmp + bps * i, data + bps * map[i], bps);
> - memcpy(data, tmp, bps * channels);
> - data += bps * channels;
> - }
> -}
> -
> #define OPUS_HEAD_SIZE 19
>
> static av_cold int libopus_decode_init(AVCodecContext *avc)
> {
> struct libopus_context *opus = avc->priv_data;
> int ret, channel_map = 0, gain_db = 0, nb_streams, nb_coupled;
> - uint8_t mapping_stereo[] = { 0, 1 }, *mapping;
> + uint8_t mapping_arr[8] = { 0, 1 }, *mapping;
>
> avc->sample_rate = 48000;
> avc->sample_fmt = avc->request_sample_fmt == AV_SAMPLE_FMT_FLT ?
> @@ -84,7 +69,17 @@ static av_cold int libopus_decode_init(AVCodecContext *avc)
> }
> nb_streams = 1;
> nb_coupled = avc->channels > 1;
> - mapping = mapping_stereo;
> + mapping = mapping_arr;
> + }
> +
> + if (avc->channels > 2 && avc->channels <= 8) {
> + const uint8_t *vorbis_offset =
> ff_vorbis_channel_layout_offsets[avc->channels - 1];
> + int ch;
> +
> + /* Remap channels from vorbis order to libav order */
> + for (ch = 0; ch < avc->channels; ch++)
> + mapping_arr[ch] = mapping[vorbis_offset[ch]];
> + mapping = mapping_arr;
> }
>
> opus->dec = opus_multistream_decoder_create(avc->sample_rate,
> avc->channels,
> @@ -144,14 +139,6 @@ static int libopus_decode(AVCodecContext *avc, void
> *frame,
> return ff_opus_error_to_averror(nb_samples);
> }
>
> - if (avc->channels > 3 && avc->channels <= 8) {
> - const uint8_t *m = ff_vorbis_channel_layout_offsets[avc->channels -
> 1];
> - if (avc->sample_fmt == AV_SAMPLE_FMT_S16)
> - reorder(opus->frame.data[0], avc->channels, 2, nb_samples, m);
> - else
> - reorder(opus->frame.data[0], avc->channels, 4, nb_samples, m);
> - }
> -
> opus->frame.nb_samples = nb_samples;
> *(AVFrame *)frame = opus->frame;
> *got_frame_ptr = 1;
Looks very good.
-Justin
_______________________________________________
libav-devel mailing list
[email protected]
https://lists.libav.org/mailman/listinfo/libav-devel
