On 2 December 2017 at 17:46, Andrew D'Addesio <modchip...@gmail.com> wrote:
> This decoder-side change, introduced in RFC 8251 (section 9), slightly > improves the decoded quality of 16kbps speech in Hybrid Mode. > > Differences can be seen/heard in testvector05.bit, testvector06.bit, > and testvector12.bit in the RFC 6716/8251 testvectors found here: > https://people.xiph.org/~greg/opus_testvectors/ > > Signed-off-by: Andrew D'Addesio <modchip...@gmail.com> > --- > libavcodec/opus_celt.c | 18 +++++++++++++++--- > 1 file changed, 15 insertions(+), 3 deletions(-) > > diff --git a/libavcodec/opus_celt.c b/libavcodec/opus_celt.c > index ff56041..2bbb96b 100644 > --- a/libavcodec/opus_celt.c > +++ b/libavcodec/opus_celt.c > @@ -712,10 +712,22 @@ static void celt_decode_bands(CeltFrame *f, > OpusRangeCoder *rc) > b = av_clip_uintp2(FFMIN(f->remaining2 + 1, f->pulses[i] + > curr_balance), 14); > } > > - if (ff_celt_freq_bands[i] - ff_celt_freq_range[i] >= > ff_celt_freq_bands[f->start_band] && > - (update_lowband || lowband_offset == 0)) > + if ((ff_celt_freq_bands[i] - ff_celt_freq_range[i] >= > ff_celt_freq_bands[f->start_band] || > + i == f->start_band + 1) && (update_lowband || lowband_offset > == 0)) > lowband_offset = i; > > + if (i == f->start_band + 1) { > + /* Special Hybrid Folding (RFC 8251 section 9). Copy the > first band into > + the second to ensure the second band never has to use the > LCG. */ > + int offset = 8 * ff_celt_freq_bands[i]; > + int count = 8 * (ff_celt_freq_range[i] - > ff_celt_freq_range[i-1]); > + > + memcpy(&norm[offset], &norm[offset - count], count * > sizeof(float)); > + > + if (f->channels == 2) > + memcpy(&norm2[offset], &norm2[offset - count], count * > sizeof(float)); > + } > + > /* Get a conservative estimate of the collapse_mask's for the > bands we're > going to be folding from. */ > if (lowband_offset != 0 && (f->spread != CELT_SPREAD_AGGRESSIVE || > @@ -728,7 +740,7 @@ static void celt_decode_bands(CeltFrame *f, > OpusRangeCoder *rc) > foldstart = lowband_offset; > while (ff_celt_freq_bands[--foldstart] > effective_lowband); > foldend = lowband_offset - 1; > - while (ff_celt_freq_bands[++foldend] < effective_lowband + > ff_celt_freq_range[i]); > + while (++foldend < i && ff_celt_freq_bands[foldend] < > effective_lowband + ff_celt_freq_range[i]); > > cm[0] = cm[1] = 0; > for (j = foldstart; j < foldend; j++) { > -- > 2.15.1.windows.2 > > _______________________________________________ > ffmpeg-devel mailing list > ffmpeg-devel@ffmpeg.org > http://ffmpeg.org/mailman/listinfo/ffmpeg-devel > Pushed, updated fate stddev scores, new decoded samples should be uploaded to fate soon too. _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel