[FFmpeg-devel] [PATCH] aactab: add and initialize 2D VLC tables for USAC Mps212

[Andreas Rheinhardt]

Lynne:
> ---
>  libavcodec/aac/aacdec_tab.c |   54 ++
>  libavcodec/aactab.c         | 1820 +++++++++++++++++++++++++++++++++++
>  libavcodec/aactab.h         |   20 +
>  3 files changed, 1894 insertions(+)
> 

1. This should only be applied if it is used which this patch does not.

> diff --git a/libavcodec/aac/aacdec_tab.c b/libavcodec/aac/aacdec_tab.c
> index 45a84a9a72..5ba20c0d8a 100644
> --- a/libavcodec/aac/aacdec_tab.c
> +++ b/libavcodec/aac/aacdec_tab.c
> @@ -111,6 +111,16 @@ const AVChannelLayout ff_aac_ch_layout[] = {
>  VLCElem ff_vlc_scalefactors[352];
>  const VLCElem *ff_vlc_spectral[11];
>  
> +const VLCElem *ff_vlc_cld_lav3_2D[2][2];
> +const VLCElem *ff_vlc_cld_lav5_2D[2][2];
> +const VLCElem *ff_vlc_cld_lav7_2D[2][2];
> +const VLCElem *ff_vlc_cld_lav9_2D[2][2];
> +
> +const VLCElem *ff_vlc_icc_lav1_2D[2][2];
> +const VLCElem *ff_vlc_icc_lav3_2D[2][2];
> +const VLCElem *ff_vlc_icc_lav5_2D[2][2];
> +const VLCElem *ff_vlc_icc_lav7_2D[2][2];
> +
>  /// Huffman tables for SBR
>  
>  static const uint8_t sbr_huffman_tab[][2] = {
> @@ -279,6 +289,50 @@ static av_cold void aacdec_common_init(void)
>                                        0);
>      }
>  
> +#define LAV_N_PAIR(NAME, NB) \
> +    ff_vlc_ ## NAME[0][0] = ff_vlc_init_tables(&state, NB, NB, \
> +                                               ff_aac_ ## NAME ## _0_0_bits, \
> +                                               sizeof(ff_aac_ ## NAME ## _0_0_bits), \
> +                                               sizeof(ff_aac_ ## NAME ## _0_0_bits), \
> +                                               ff_aac_ ## NAME ## _0_0_codes, \
> +                                               sizeof(ff_aac_ ## NAME ## _0_0_codes), \
> +                                               sizeof(ff_aac_ ## NAME ## _0_0_codes), \
> +                                               0); \
> +    ff_vlc_ ## NAME[0][1] = ff_vlc_init_tables(&state, NB, NB, \
> +                                               ff_aac_ ## NAME ## _0_1_bits, \
> +                                               sizeof(ff_aac_ ## NAME ## _0_1_bits), \
> +                                               sizeof(ff_aac_ ## NAME ## _0_1_bits), \
> +                                               ff_aac_ ## NAME ## _0_1_codes, \
> +                                               sizeof(ff_aac_ ## NAME ## _0_1_codes), \
> +                                               sizeof(ff_aac_ ## NAME ## _0_1_codes), \
> +                                               0); \
> +    ff_vlc_ ## NAME[1][0] = ff_vlc_init_tables(&state, NB, NB, \
> +                                               ff_aac_ ## NAME ## _1_0_bits, \
> +                                               sizeof(ff_aac_ ## NAME ## _1_0_bits), \
> +                                               sizeof(ff_aac_ ## NAME ## _1_0_bits), \
> +                                               ff_aac_ ## NAME ## _1_0_codes, \
> +                                               sizeof(ff_aac_ ## NAME ## _1_0_codes), \
> +                                               sizeof(ff_aac_ ## NAME ## _1_0_codes), \
> +                                               0); \
> +    ff_vlc_ ## NAME[1][1] = ff_vlc_init_tables(&state, NB, NB, \
> +                                               ff_aac_ ## NAME ## _1_1_bits, \
> +                                               sizeof(ff_aac_ ## NAME ## _1_1_bits), \
> +                                               sizeof(ff_aac_ ## NAME ## _1_1_bits), \
> +                                               ff_aac_ ## NAME ## _1_1_codes, \
> +                                               sizeof(ff_aac_ ## NAME ## _1_1_codes), \
> +                                               sizeof(ff_aac_ ## NAME ## _1_1_codes), \
> +                                               0);

2. I am very much surprised that it works at all (does it?). You use the
same state and therefore the same static storage as before; you add new
VLCs, yet you do not increase the size of vlc_buf.
3. Can't you initialize this in a loop like ff_aac_sbr_vlc? This would
remove code duplication as well as relocations.


> +
> +    LAV_N_PAIR(icc_lav1_2D, 8)
> +    LAV_N_PAIR(icc_lav3_2D, 8)
> +    LAV_N_PAIR(icc_lav5_2D, 8)
> +    LAV_N_PAIR(icc_lav7_2D, 8)
> +
> +    LAV_N_PAIR(cld_lav3_2D, 8)
> +    LAV_N_PAIR(cld_lav5_2D, 8)
> +    LAV_N_PAIR(cld_lav7_2D, 8)
> +    LAV_N_PAIR(cld_lav9_2D, 8)
> +
>      VLC_INIT_STATIC_TABLE(ff_vlc_scalefactors, 7,
>                            FF_ARRAY_ELEMS(ff_aac_scalefactor_code),
>                            ff_aac_scalefactor_bits,