[FFmpeg-devel] [PATCH 14/25] avcodec/utvideodec: Remove code duplication when creating Huffman tables

[Paul B Mahol]

On Sat, Sep 26, 2020 at 12:27:53PM +0200, Andreas Rheinhardt wrote:
> Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at gmail.com>
> ---
>  libavcodec/utvideodec.c | 55 +++++------------------------------------
>  1 file changed, 6 insertions(+), 49 deletions(-)
> 

lgtm

> diff --git a/libavcodec/utvideodec.c b/libavcodec/utvideodec.c
> index b3c4c3519b..f014e90606 100644
> --- a/libavcodec/utvideodec.c
> +++ b/libavcodec/utvideodec.c
> @@ -40,7 +40,7 @@
>  #include "thread.h"
>  #include "utvideo.h"
>  
> -static int build_huff10(const uint8_t *src, VLC *vlc, int *fsym)
> +static int build_huff(const uint8_t *src, VLC *vlc, int *fsym, unsigned nb_elems)
>  {
>      int i;
>      HuffEntry he[1024];
> @@ -51,18 +51,18 @@ static int build_huff10(const uint8_t *src, VLC *vlc, int *fsym)
>      uint32_t code;
>  
>      *fsym = -1;
> -    for (i = 0; i < 1024; i++) {
> +    for (i = 0; i < nb_elems; i++) {
>          he[i].sym = i;
>          he[i].len = *src++;
>      }
> -    qsort(he, 1024, sizeof(*he), ff_ut10_huff_cmp_len);
> +    qsort(he, nb_elems, sizeof(*he), ff_ut10_huff_cmp_len);
>  
>      if (!he[0].len) {
>          *fsym = he[0].sym;
>          return 0;
>      }
>  
> -    last = 1023;
> +    last = nb_elems - 1;
>      while (he[last].len == 255 && last)
>          last--;
>  
> @@ -84,49 +84,6 @@ static int build_huff10(const uint8_t *src, VLC *vlc, int *fsym)
>                                syms,  sizeof(*syms),  sizeof(*syms), 0);
>  }
>  
> -static int build_huff(const uint8_t *src, VLC *vlc, int *fsym)
> -{
> -    int i;
> -    HuffEntry he[256];
> -    int last;
> -    uint32_t codes[256];
> -    uint8_t bits[256];
> -    uint8_t syms[256];
> -    uint32_t code;
> -
> -    *fsym = -1;
> -    for (i = 0; i < 256; i++) {
> -        he[i].sym = i;
> -        he[i].len = *src++;
> -    }
> -    qsort(he, 256, sizeof(*he), ff_ut_huff_cmp_len);
> -
> -    if (!he[0].len) {
> -        *fsym = he[0].sym;
> -        return 0;
> -    }
> -
> -    last = 255;
> -    while (he[last].len == 255 && last)
> -        last--;
> -
> -    if (he[last].len > 32)
> -        return -1;
> -
> -    code = 0;
> -    for (i = last; i >= 0; i--) {
> -        codes[i] = code >> (32 - he[i].len);
> -        bits[i]  = he[i].len;
> -        syms[i]  = he[i].sym;
> -        code += 0x80000000u >> (he[i].len - 1);
> -    }
> -
> -    return ff_init_vlc_sparse(vlc, VLC_BITS, last + 1,
> -                              bits,  sizeof(*bits),  sizeof(*bits),
> -                              codes, sizeof(*codes), sizeof(*codes),
> -                              syms,  sizeof(*syms),  sizeof(*syms), 0);
> -}
> -
>  static int decode_plane10(UtvideoContext *c, int plane_no,
>                            uint16_t *dst, ptrdiff_t stride,
>                            int width, int height,
> @@ -139,7 +96,7 @@ static int decode_plane10(UtvideoContext *c, int plane_no,
>      GetBitContext gb;
>      int prev, fsym;
>  
> -    if ((ret = build_huff10(huff, &vlc, &fsym)) < 0) {
> +    if ((ret = build_huff(huff, &vlc, &fsym, 1024)) < 0) {
>          av_log(c->avctx, AV_LOG_ERROR, "Cannot build Huffman codes\n");
>          return ret;
>      }
> @@ -299,7 +256,7 @@ static int decode_plane(UtvideoContext *c, int plane_no,
>          return 0;
>      }
>  
> -    if (build_huff(src, &vlc, &fsym)) {
> +    if (build_huff(src, &vlc, &fsym, 256)) {
>          av_log(c->avctx, AV_LOG_ERROR, "Cannot build Huffman codes\n");
>          return AVERROR_INVALIDDATA;
>      }
> -- 
> 2.25.1
> 
> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel at ffmpeg.org
> https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
> 
> To unsubscribe, visit link above, or email
> ffmpeg-devel-request at ffmpeg.org with subject "unsubscribe".