[FFmpeg-devel] [PATCH 1/2] avcodec/dnxhdenc: Move PutBitContext from ctx to stack

[Vittorio Giovara]

On Sat, Jun 8, 2024 at 9:45 PM Andreas Rheinhardt <
andreas.rheinhardt at outlook.com> wrote:

> Andreas Rheinhardt:
> > Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at outlook.com>
> > ---
> >  libavcodec/dnxhdenc.c | 33 +++++++++++++++++----------------
> >  1 file changed, 17 insertions(+), 16 deletions(-)
> >
> > diff --git a/libavcodec/dnxhdenc.c b/libavcodec/dnxhdenc.c
> > index 0cb25d7714..4760a2932c 100644
> > --- a/libavcodec/dnxhdenc.c
> > +++ b/libavcodec/dnxhdenc.c
> > @@ -559,7 +559,7 @@ static int dnxhd_write_header(AVCodecContext *avctx,
> uint8_t *buf)
> >      return 0;
> >  }
> >
> > -static av_always_inline void dnxhd_encode_dc(DNXHDEncContext *ctx, int
> diff)
> > +static av_always_inline void dnxhd_encode_dc(PutBitContext *pb,
> DNXHDEncContext *ctx, int diff)
> >  {
> >      int nbits;
> >      if (diff < 0) {
> > @@ -568,19 +568,19 @@ static av_always_inline void
> dnxhd_encode_dc(DNXHDEncContext *ctx, int diff)
> >      } else {
> >          nbits = av_log2_16bit(2 * diff);
> >      }
> > -    put_bits(&ctx->m.pb, ctx->cid_table->dc_bits[nbits] + nbits,
> > +    put_bits(pb, ctx->cid_table->dc_bits[nbits] + nbits,
> >               (ctx->cid_table->dc_codes[nbits] << nbits) +
> >               av_mod_uintp2(diff, nbits));
> >  }
> >
> >  static av_always_inline
> > -void dnxhd_encode_block(DNXHDEncContext *ctx, int16_t *block,
> > -                        int last_index, int n)
> > +void dnxhd_encode_block(PutBitContext *pb, DNXHDEncContext *ctx,
> > +                        int16_t *block, int last_index, int n)
> >  {
> >      int last_non_zero = 0;
> >      int slevel, i, j;
> >
> > -    dnxhd_encode_dc(ctx, block[0] - ctx->m.last_dc[n]);
> > +    dnxhd_encode_dc(pb, ctx, block[0] - ctx->m.last_dc[n]);
> >      ctx->m.last_dc[n] = block[0];
> >
> >      for (i = 1; i <= last_index; i++) {
> > @@ -589,14 +589,14 @@ void dnxhd_encode_block(DNXHDEncContext *ctx,
> int16_t *block,
> >          if (slevel) {
> >              int run_level = i - last_non_zero - 1;
> >              int rlevel = slevel * (1 << 1) | !!run_level;
> > -            put_bits(&ctx->m.pb, ctx->vlc_bits[rlevel],
> ctx->vlc_codes[rlevel]);
> > +            put_bits(pb, ctx->vlc_bits[rlevel], ctx->vlc_codes[rlevel]);
> >              if (run_level)
> > -                put_bits(&ctx->m.pb, ctx->run_bits[run_level],
> > +                put_bits(pb, ctx->run_bits[run_level],
> >                           ctx->run_codes[run_level]);
> >              last_non_zero = i;
> >          }
> >      }
> > -    put_bits(&ctx->m.pb, ctx->vlc_bits[0], ctx->vlc_codes[0]); // EOB
> > +    put_bits(pb, ctx->vlc_bits[0], ctx->vlc_codes[0]); // EOB
> >  }
> >
> >  static av_always_inline
> > @@ -879,9 +879,10 @@ static int dnxhd_encode_thread(AVCodecContext
> *avctx, void *arg,
> >                                 int jobnr, int threadnr)
> >  {
> >      DNXHDEncContext *ctx = avctx->priv_data;
> > +    PutBitContext pb0, *const pb = &pb0;
> >      int mb_y = jobnr, mb_x;
> >      ctx = ctx->thread[threadnr];
> > -    init_put_bits(&ctx->m.pb, (uint8_t *)arg + ctx->data_offset +
> ctx->slice_offs[jobnr],
> > +    init_put_bits(pb, (uint8_t *)arg + ctx->data_offset +
> ctx->slice_offs[jobnr],
> >                    ctx->slice_size[jobnr]);
> >
> >      ctx->m.last_dc[0] =
> > @@ -892,8 +893,8 @@ static int dnxhd_encode_thread(AVCodecContext
> *avctx, void *arg,
> >          int qscale = ctx->mb_qscale[mb];
> >          int i;
> >
> > -        put_bits(&ctx->m.pb, 11, qscale);
> > -        put_bits(&ctx->m.pb, 1, avctx->pix_fmt == AV_PIX_FMT_YUV444P10);
> > +        put_bits(pb, 11, qscale);
> > +        put_bits(pb, 1, avctx->pix_fmt == AV_PIX_FMT_YUV444P10);
> >
> >          dnxhd_get_blocks(ctx, mb_x, mb_y);
> >
> > @@ -904,13 +905,13 @@ static int dnxhd_encode_thread(AVCodecContext
> *avctx, void *arg,
> >                                                   ctx->is_444 ? (((i >>
> 1) % 3) < 1 ? 0 : 4): 4 & (2*i),
> >                                                   qscale, &overflow);
> >
> > -            dnxhd_encode_block(ctx, block, last_index, n);
> > +            dnxhd_encode_block(pb, ctx, block, last_index, n);
> >          }
> >      }
> > -    if (put_bits_count(&ctx->m.pb) & 31)
> > -        put_bits(&ctx->m.pb, 32 - (put_bits_count(&ctx->m.pb) & 31), 0);
> > -    flush_put_bits(&ctx->m.pb);
> > -    memset(put_bits_ptr(&ctx->m.pb), 0, put_bytes_left(&ctx->m.pb, 0));
> > +    if (put_bits_count(pb) & 31)
> > +        put_bits(pb, 32 - (put_bits_count(pb) & 31), 0);
> > +    flush_put_bits(pb);
> > +    memset(put_bits_ptr(pb), 0, put_bytes_left(pb, 0));
> >      return 0;
> >  }
> >
>
> Will apply this patchset tomorrow unless there are objections.
>

No objections, but what is the rationale here? Just reducing variables
scope?
-- 
Vittorio