[FFmpeg-devel] [PATCH] avcodec/dvdec: correctly decode bottom mb row in 1080i field mode

Baptiste Coudurier baptiste.coudurier at gmail.com
Sat Nov 2 21:02:03 EET 2019


On Wed, Sep 11, 2019 at 12:29 PM Baptiste Coudurier <
baptiste.coudurier at gmail.com> wrote:

> ---
>  libavcodec/dv.h    |  2 ++
>  libavcodec/dvdec.c | 90 +++++++++++++++++++++++++++++++++++-----------
>  2 files changed, 72 insertions(+), 20 deletions(-)
>
> diff --git a/libavcodec/dv.h b/libavcodec/dv.h
> index 0e97bb200e..7ef5b7c552 100644
> --- a/libavcodec/dv.h
> +++ b/libavcodec/dv.h
> @@ -31,6 +31,7 @@
>  #include "dv_profile.h"
>  #include "me_cmp.h"
>  #include "vlc.h"
> +#include "idctdsp.h"
>
>  typedef struct DVwork_chunk {
>      uint16_t buf_offset;
> @@ -52,6 +53,7 @@ typedef struct DVVideoContext {
>      me_cmp_func ildct_cmp;
>      DVwork_chunk work_chunks[4 * 12 * 27];
>      uint32_t idct_factor[2 * 4 * 16 * 64];
> +    IDCTDSPContext idsp;
>
>      int quant_deadzone;
>  } DVVideoContext;
> diff --git a/libavcodec/dvdec.c b/libavcodec/dvdec.c
> index 89864f2edc..4345cd9e29 100644
> --- a/libavcodec/dvdec.c
> +++ b/libavcodec/dvdec.c
> @@ -45,7 +45,6 @@
>  #include "dv_profile_internal.h"
>  #include "dvdata.h"
>  #include "get_bits.h"
> -#include "idctdsp.h"
>  #include "internal.h"
>  #include "put_bits.h"
>  #include "simple_idct.h"
> @@ -177,24 +176,22 @@ static void dv_init_weight_tables(DVVideoContext
> *ctx, const AVDVProfile *d)
>  static av_cold int dvvideo_decode_init(AVCodecContext *avctx)
>  {
>      DVVideoContext *s = avctx->priv_data;
> -    IDCTDSPContext idsp;
>      int i;
>
> -    memset(&idsp,0, sizeof(idsp));
> -    ff_idctdsp_init(&idsp, avctx);
> +    ff_idctdsp_init(&s->idsp, avctx);
>
>      for (i = 0; i < 64; i++)
> -        s->dv_zigzag[0][i] = idsp.idct_permutation[ff_zigzag_direct[i]];
> +        s->dv_zigzag[0][i] =
> s->idsp.idct_permutation[ff_zigzag_direct[i]];
>
>      if (avctx->lowres){
>          for (i = 0; i < 64; i++){
>              int j = ff_dv_zigzag248_direct[i];
> -            s->dv_zigzag[1][i] = idsp.idct_permutation[(j & 7) + (j & 8)
> * 4 + (j & 48) / 2];
> +            s->dv_zigzag[1][i] = s->idsp.idct_permutation[(j & 7) + (j &
> 8) * 4 + (j & 48) / 2];
>          }
>      }else
>          memcpy(s->dv_zigzag[1], ff_dv_zigzag248_direct,
> sizeof(s->dv_zigzag[1]));
>
> -    s->idct_put[0] = idsp.idct_put;
> +    s->idct_put[0] = s->idsp.idct_put;
>      s->idct_put[1] = ff_simple_idct248_put;
>
>      return ff_dvvideo_init(avctx);
> @@ -272,6 +269,49 @@ static inline void bit_copy(PutBitContext *pb,
> GetBitContext *gb)
>          put_bits(pb, bits_left, get_bits(gb, bits_left));
>  }
>
> +static av_always_inline void put_block_8x4(int16_t *block, uint8_t
> *restrict p, int stride)
> +{
> +    int i, j;
> +    const uint8_t *cm = ff_crop_tab + MAX_NEG_CROP;
> +
> +    for (i = 0; i < 4; i++) {
> +        for (j = 0; j < 8; j++)
> +            p[j] = cm[block[j]];
> +        block += 8;
> +        p += stride;
> +    }
> +}
> +
> +static void dv100_idct_put_last_row_field_chroma(DVVideoContext *s,
> uint8_t *data,
> +                                                 int stride, int16_t
> *blocks)
> +{
> +    s->idsp.idct(blocks + 0*64);
> +    s->idsp.idct(blocks + 1*64);
> +
> +    put_block_8x4(blocks+0*64,       data,              stride<<1);
> +    put_block_8x4(blocks+0*64 + 4*8, data + 8,          stride<<1);
> +    put_block_8x4(blocks+1*64,       data + stride,     stride<<1);
> +    put_block_8x4(blocks+1*64 + 4*8, data + 8 + stride, stride<<1);
> +}
> +
> +static void dv100_idct_put_last_row_field_luma(DVVideoContext *s, uint8_t
> *data,
> +                                               int stride, int16_t
> *blocks)
> +{
> +    s->idsp.idct(blocks + 0*64);
> +    s->idsp.idct(blocks + 1*64);
> +    s->idsp.idct(blocks + 2*64);
> +    s->idsp.idct(blocks + 3*64);
> +
> +    put_block_8x4(blocks+0*64,       data,               stride<<1);
> +    put_block_8x4(blocks+0*64 + 4*8, data + 16,          stride<<1);
> +    put_block_8x4(blocks+1*64,       data + 8,           stride<<1);
> +    put_block_8x4(blocks+1*64 + 4*8, data + 24,          stride<<1);
> +    put_block_8x4(blocks+2*64,       data + stride,      stride<<1);
> +    put_block_8x4(blocks+2*64 + 4*8, data + 16 + stride, stride<<1);
> +    put_block_8x4(blocks+3*64,       data + 8  + stride, stride<<1);
> +    put_block_8x4(blocks+3*64 + 4*8, data + 24 + stride, stride<<1);
> +}
> +
>  /* mb_x and mb_y are in units of 8 pixels */
>  static int dv_decode_video_segment(AVCodecContext *avctx, void *arg)
>  {
> @@ -443,14 +483,18 @@ retry:
>          }
>          y_ptr    = s->frame->data[0] +
>                     ((mb_y * s->frame->linesize[0] + mb_x) <<
> log2_blocksize);
> -        linesize = s->frame->linesize[0] << is_field_mode[mb_index];
> -        mb[0].idct_put(y_ptr, linesize, block + 0 * 64);
> -        if (s->sys->video_stype == 4) { /* SD 422 */
> -            mb[2].idct_put(y_ptr + (1 << log2_blocksize),
> linesize, block + 2 * 64);
> +        if (mb_y == 134 && is_field_mode[mb_index]) {
> +            dv100_idct_put_last_row_field_luma(s, y_ptr,
> s->frame->linesize[0], block);
>          } else {
> -            mb[1].idct_put(y_ptr + (1 << log2_blocksize),
> linesize, block + 1 * 64);
> -            mb[2].idct_put(y_ptr                         + y_stride,
> linesize, block + 2 * 64);
> -            mb[3].idct_put(y_ptr + (1 << log2_blocksize) + y_stride,
> linesize, block + 3 * 64);
> +            linesize = s->frame->linesize[0] << is_field_mode[mb_index];
> +            mb[0].idct_put(y_ptr, linesize, block + 0 * 64);
> +            if (s->sys->video_stype == 4) { /* SD 422 */
> +                mb[2].idct_put(y_ptr + (1 << log2_blocksize),
> linesize, block + 2 * 64);
> +            } else {
> +                mb[1].idct_put(y_ptr + (1 << log2_blocksize),
> linesize, block + 1 * 64);
> +                mb[2].idct_put(y_ptr                         + y_stride,
> linesize, block + 2 * 64);
> +                mb[3].idct_put(y_ptr + (1 << log2_blocksize) + y_stride,
> linesize, block + 3 * 64);
> +            }
>          }
>          mb    += 4;
>          block += 4 * 64;
> @@ -478,13 +522,19 @@ retry:
>                  mb++;
>              } else {
>                  y_stride = (mb_y == 134) ? (1 << log2_blocksize) :
> -                           s->frame->linesize[j] <<
> ((!is_field_mode[mb_index]) * log2_blocksize);
> -                linesize = s->frame->linesize[j] <<
> is_field_mode[mb_index];
> -                (mb++)->idct_put(c_ptr, linesize, block);
> -                block += 64;
> -                if (s->sys->bpm == 8) {
> -                    (mb++)->idct_put(c_ptr + y_stride, linesize, block);
> +                    s->frame->linesize[j] << ((!is_field_mode[mb_index])
> * log2_blocksize);
> +                if (mb_y == 134 && is_field_mode[mb_index]) {
> +                    dv100_idct_put_last_row_field_chroma(s, c_ptr,
> s->frame->linesize[j], block);
> +                    mb += 2;
> +                    block += 2*64;
> +                } else {
> +                    linesize = s->frame->linesize[j] <<
> is_field_mode[mb_index];
> +                    (mb++)->idct_put(c_ptr, linesize, block);
>                      block += 64;
> +                    if (s->sys->bpm == 8) {
> +                        (mb++)->idct_put(c_ptr + y_stride, linesize,
> block);
> +                        block += 64;
> +                    }
>                  }
>              }
>          }
> --
> 2.20.1 (Apple Git-117)
>

 Will apply

-- 
Baptiste


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