Re: [FFmpeg-devel] [PATCH v4 3/3] lavc/dxvenc: improve compatibility with Resolume products

[Andreas Rheinhardt <andreas.rheinhardt@outlook.com>]

Emma Worley:
> Improves compatibility with Resolume products by adding an additional
> hashtable for DXT color+LUT combinations, and padding the DXT texture
> dimensions to the next largest multiple of 16. Produces identical
> packets to Resolume Alley in manual tests.
> 
> Signed-off-by: Emma Worley <emma@emma.gg>
> ---
>  libavcodec/dxvenc.c         | 131 +++++++++++++++++++++++-------------
>  tests/ref/fate/dxv3enc-dxt1 |   2 +-
>  2 files changed, 86 insertions(+), 47 deletions(-)
> 
> diff --git a/libavcodec/dxvenc.c b/libavcodec/dxvenc.c
> index 207ac1f24f..48548ae811 100644
> --- a/libavcodec/dxvenc.c
> +++ b/libavcodec/dxvenc.c
> @@ -34,6 +34,11 @@
>  
>  #define DXV_HEADER_LENGTH 12
>  
> +/*
> + * Resolume will refuse to display frames that are not padded to 16x16 pixels.
> + */
> +#define DXV_ALIGN(x) FFALIGN(x, 16)
> +
>  /*
>   * DXV uses LZ-like back-references to avoid copying words that have already
>   * appeared in the decompressed stream. Using a simple hash table (HT)
> @@ -60,6 +65,7 @@ typedef struct DXVEncContext {
>  
>      struct FFHashtableContext *color_ht;
>      struct FFHashtableContext *lut_ht;
> +    struct FFHashtableContext *combo_ht;
>  } DXVEncContext;
>  
>  /* Converts an index offset value to a 2-bit opcode and pushes it to a stream.
> @@ -94,10 +100,14 @@ static int dxv_compress_dxt1(AVCodecContext *avctx)
>      DXVEncContext *ctx = avctx->priv_data;
>      PutByteContext *pbc = &ctx->pbc;
>      void *value;
> -    uint32_t color, lut, idx, color_idx, lut_idx, prev_pos, state = 16, pos = 0, op = 0;
> +    uint64_t combo;
> +    uint32_t color, lut, idx, combo_idx, prev_pos, old_pos, state = 16, pos = 0, op = 0;
>  
>      ff_hashtable_clear(ctx->color_ht);
>      ff_hashtable_clear(ctx->lut_ht);
> +    ff_hashtable_clear(ctx->combo_ht);
> +
> +    ff_hashtable_set(ctx->combo_ht, ctx->tex_data, &pos);
>  
>      bytestream2_put_le32(pbc, AV_RL32(ctx->tex_data));
>      ff_hashtable_set(ctx->color_ht, ctx->tex_data, &pos);
> @@ -107,51 +117,46 @@ static int dxv_compress_dxt1(AVCodecContext *avctx)
>      pos++;
>  
>      while (pos + 2 <= ctx->tex_size / 4) {
> -        idx = 0;
> -        color_idx = 0;
> -        lut_idx = 0;
> +        combo = AV_RL64(ctx->tex_data + pos * 4);
> +        combo_idx = ff_hashtable_get(ctx->combo_ht, &combo, &prev_pos) ? pos - prev_pos : 0;
> +        idx = combo_idx;
> +        PUSH_OP(2);
> +        if (pos >= LOOKBACK_WORDS) {
> +            old_pos = pos - LOOKBACK_WORDS;
> +            if (ff_hashtable_get(ctx->combo_ht, ctx->tex_data + old_pos * 4, &prev_pos) && prev_pos <= old_pos)
> +                ff_hashtable_delete(ctx->combo_ht, ctx->tex_data + old_pos * 4);
> +        }
> +        ff_hashtable_set(ctx->combo_ht, &combo, &pos);
>  
>          color = AV_RL32(ctx->tex_data + pos * 4);
> -        if (ff_hashtable_get(ctx->color_ht, &color, &prev_pos))
> -            color_idx = pos - prev_pos;
> -        ff_hashtable_set(ctx->color_ht, &color, &pos);
> -
> +        if (!combo_idx) {
> +            idx = ff_hashtable_get(ctx->color_ht, &color, &prev_pos) ? pos - prev_pos : 0;
> +            PUSH_OP(2);
> +            if (!idx)
> +                bytestream2_put_le32(pbc, color);
> +        }
>          if (pos >= LOOKBACK_WORDS) {
> -            uint32_t old_pos = pos - LOOKBACK_WORDS;
> +            old_pos = pos - LOOKBACK_WORDS;
>              if (ff_hashtable_get(ctx->color_ht, ctx->tex_data + old_pos * 4, &prev_pos) && prev_pos <= old_pos)
>                  ff_hashtable_delete(ctx->color_ht, ctx->tex_data + old_pos * 4);
>          }
> +        ff_hashtable_set(ctx->color_ht, &color, &pos);
>          pos++;
>  
>          lut = AV_RL32(ctx->tex_data + pos * 4);
> -        if (color_idx && lut == AV_RL32(ctx->tex_data + (pos - color_idx) * 4)) {
> -            idx = color_idx;
> -        } else {
> -            idx = 0;
> -            if (ff_hashtable_get(ctx->lut_ht, &lut, &prev_pos))
> -                lut_idx = pos - prev_pos;
> -            ff_hashtable_set(ctx->lut_ht, &lut, &pos);
> +        if (!combo_idx) {
> +            idx = ff_hashtable_get(ctx->lut_ht, &lut, &prev_pos) ? pos - prev_pos : 0;
> +            PUSH_OP(2);
> +            if (!idx)
> +                bytestream2_put_le32(pbc, lut);
>          }
>          if (pos >= LOOKBACK_WORDS) {
> -            uint32_t old_pos = pos - LOOKBACK_WORDS;
> +            old_pos = pos - LOOKBACK_WORDS;
>              if (ff_hashtable_get(ctx->lut_ht, ctx->tex_data + old_pos * 4, &prev_pos) && prev_pos <= old_pos)
>                  ff_hashtable_delete(ctx->lut_ht, ctx->tex_data + old_pos * 4);
>          }
> +        ff_hashtable_set(ctx->lut_ht, &lut, &pos);
>          pos++;
> -
> -        PUSH_OP(2);
> -
> -        if (!idx) {
> -            idx = color_idx;
> -            PUSH_OP(2);
> -            if (!idx)
> -                bytestream2_put_le32(pbc,  color);
> -
> -            idx = lut_idx;
> -            PUSH_OP(2);
> -            if (!idx)
> -                bytestream2_put_le32(pbc,  lut);
> -        }
>      }
>  
>      return 0;
> @@ -172,12 +177,50 @@ static int dxv_encode(AVCodecContext *avctx, AVPacket *pkt,
>          return ret;
>  
>      if (ctx->enc.tex_funct) {
> +        uint8_t *safe_data[4] = {frame->data[0], 0, 0, 0};
> +        int safe_linesize[4] = {frame->linesize[0], 0, 0, 0};
> +
> +        if (avctx->width != DXV_ALIGN(avctx->width) || avctx->height != DXV_ALIGN(avctx->height)) {
> +            ret = av_image_alloc(
> +                safe_data,
> +                safe_linesize,
> +                DXV_ALIGN(avctx->width),
> +                DXV_ALIGN(avctx->height),
> +                avctx->pix_fmt,
> +                1);
> +            if (ret < 0)
> +                return ret;
> +
> +            av_image_copy2(
> +                safe_data,
> +                safe_linesize,
> +                frame->data,
> +                frame->linesize,
> +                avctx->pix_fmt,
> +                avctx->width,
> +                avctx->height);
> +
> +            if (avctx->width != DXV_ALIGN(avctx->width)) {
> +                for (int y = 0; y < avctx->height; y++) {
> +                    memset(safe_data[0] + y * safe_linesize[0] + frame->linesize[0], 0, safe_linesize[0] - frame->linesize[0]);
> +                }
> +            }
> +            if (avctx->height != DXV_ALIGN(avctx->height)) {
> +                for (int y = avctx->height; y < DXV_ALIGN(avctx->height); y++) {
> +                    memset(safe_data[0] + y * safe_linesize[0], 0, safe_linesize[0]);
> +                }
> +            }
> +        }

Did you try to avoid the above by modifying
ff_texturedsp_exec_compress_threads()?

> +
>          ctx->enc.tex_data.out = ctx->tex_data;
> -        ctx->enc.frame_data.in = frame->data[0];
> -        ctx->enc.stride = frame->linesize[0];
> -        ctx->enc.width  = avctx->width;
> -        ctx->enc.height = avctx->height;
> +        ctx->enc.frame_data.in = safe_data[0];
> +        ctx->enc.stride = safe_linesize[0];
> +        ctx->enc.width  = DXV_ALIGN(avctx->width);
> +        ctx->enc.height = DXV_ALIGN(avctx->height);
>          ff_texturedsp_exec_compress_threads(avctx, &ctx->enc);
> +
> +        if (safe_data[0] != frame->data[0])
> +            av_freep(&safe_data[0]);
>      } else {
>          /* unimplemented: YCoCg formats */
>          return AVERROR_INVALIDDATA;
> @@ -216,14 +259,6 @@ static av_cold int dxv_init(AVCodecContext *avctx)
>          return ret;
>      }
>  
> -    if (avctx->width % TEXTURE_BLOCK_W || avctx->height % TEXTURE_BLOCK_H) {
> -        av_log(avctx,
> -               AV_LOG_ERROR,
> -               "Video size %dx%d is not multiple of "AV_STRINGIFY(TEXTURE_BLOCK_W)"x"AV_STRINGIFY(TEXTURE_BLOCK_H)".\n",
> -               avctx->width, avctx->height);
> -        return AVERROR_INVALIDDATA;
> -    }
> -
>      ff_texturedspenc_init(&texdsp);
>  
>      switch (ctx->tex_fmt) {
> @@ -237,10 +272,10 @@ static av_cold int dxv_init(AVCodecContext *avctx)
>          return AVERROR_INVALIDDATA;
>      }
>      ctx->enc.raw_ratio = 16;
> -    ctx->tex_size = avctx->width  / TEXTURE_BLOCK_W *
> -                    avctx->height / TEXTURE_BLOCK_H *
> +    ctx->tex_size = DXV_ALIGN(avctx->width) / TEXTURE_BLOCK_W *
> +                    DXV_ALIGN(avctx->height) / TEXTURE_BLOCK_H *
>                      ctx->enc.tex_ratio;
> -    ctx->enc.slice_count = av_clip(avctx->thread_count, 1, avctx->height / TEXTURE_BLOCK_H);
> +    ctx->enc.slice_count = av_clip(avctx->thread_count, 1, DXV_ALIGN(avctx->height) / TEXTURE_BLOCK_H);
>  
>      ctx->tex_data = av_malloc(ctx->tex_size);
>      if (!ctx->tex_data) {
> @@ -251,6 +286,9 @@ static av_cold int dxv_init(AVCodecContext *avctx)
>      if (ret < 0)
>          return ret;
>      ret = ff_hashtable_alloc(&ctx->lut_ht, sizeof(uint32_t), sizeof(uint32_t), LOOKBACK_HT_ELEMS);
> +    if (ret < 0)
> +        return ret;
> +    ret = ff_hashtable_alloc(&ctx->combo_ht, sizeof(uint64_t), sizeof(uint32_t), LOOKBACK_HT_ELEMS);
>      if (ret < 0)
>          return ret;
>  
> @@ -265,6 +303,7 @@ static av_cold int dxv_close(AVCodecContext *avctx)
>  
>      ff_hashtable_freep(&ctx->color_ht);
>      ff_hashtable_freep(&ctx->lut_ht);
> +    ff_hashtable_freep(&ctx->combo_ht);
>  
>      return 0;
>  }
> diff --git a/tests/ref/fate/dxv3enc-dxt1 b/tests/ref/fate/dxv3enc-dxt1
> index 74849a8031..e09000e181 100644
> --- a/tests/ref/fate/dxv3enc-dxt1
> +++ b/tests/ref/fate/dxv3enc-dxt1
> @@ -3,4 +3,4 @@
>  #codec_id 0: dxv
>  #dimensions 0: 1920x1080
>  #sar 0: 1/1
> -0,          0,          0,        1,    76521, 0xed387a5e
> +0,          0,          0,        1,    76190, 0x0e6f0326

_______________________________________________
ffmpeg-devel mailing list
ffmpeg-devel@ffmpeg.org
https://ffmpeg.org/mailman/listinfo/ffmpeg-devel

To unsubscribe, visit link above, or email
ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".