On 12 July 2017 at 23:18, Tyler Jones <tdjones...@gmail.com> wrote:
> Additional codebooks are added for shorter 128-sample frames. Changes in
> codeword generation are made to handle valid values of 0 that prepend some
> codebooks, otherwise books are classified incorrectly and cause unreadable
> streams.
>
> A second residue, floor, and mapping is created for short window lengths
> so that values are partitioned correctly for transient frames.
>
> Signed-off-by: Tyler Jones <tdjones...@gmail.com>
> ---
> libavcodec/vorbis.c | 10 +-
> libavcodec/vorbis_enc_data.h | 289 +++++++++++++++++++----------
> libavcodec/vorbisenc.c | 422 ++++++++++++++++++++++++++----
> -------------
> tests/fate/vorbis.mak | 2 +-
> 4 files changed, 453 insertions(+), 270 deletions(-)
>
> diff --git a/libavcodec/vorbis.c b/libavcodec/vorbis.c
> index 399020e..8befab8 100644
> --- a/libavcodec/vorbis.c
> +++ b/libavcodec/vorbis.c
> @@ -59,7 +59,7 @@ int ff_vorbis_len2vlc(uint8_t *bits, uint32_t *codes,
> unsigned num)
> unsigned i, j, p, code;
>
> for (p = 0; (bits[p] == 0) && (p < num); ++p)
> - ;
> + codes[p] = 0;
> if (p == num)
> return 0;
>
> @@ -78,9 +78,11 @@ int ff_vorbis_len2vlc(uint8_t *bits, uint32_t *codes,
> unsigned num)
>
> for (; p < num; ++p) {
> if (bits[p] > 32)
> - return AVERROR_INVALIDDATA;
> - if (bits[p] == 0)
> - continue;
> + return AVERROR_INVALIDDATA;
> + if (bits[p] == 0) {
> + codes[p] = 0;
> + continue;
> + }
>
I prefer the if (!bits[p]) way of checking for 0. Most of the codebase does
so too.
> // find corresponding exit(node which the tree can grow further
> from)
> for (i = bits[p]; i > 0; --i)
> if (exit_at_level[i])
> diff --git a/libavcodec/vorbis_enc_data.h b/libavcodec/vorbis_enc_data.h
> index a51aaec..eca43df 100644
> --- a/libavcodec/vorbis_enc_data.h
> +++ b/libavcodec/vorbis_enc_data.h
> @@ -23,15 +23,78 @@
>
> #include <stdint.h>
>
> <TABLE CHANGES>
>
Could you move the tables to vorbis_data.c and delete vorbis_enc_data.h?
Would be neater.
Apart from those nits, patch would be fine for merging as well.
It improves quality in some ways however it introduces some clicking which
I believe is due to the lack of stability.
I think you can improve this by tweaking the constants in the previous
patch and by reducing the fluctuations between
transient and non-transient frames. Its better to have a whole series of
transients rather than interrupting them with non-transients, and vice
versa.
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