[FFmpeg-devel] [PATCH v2 3/3] lavc/dxvenc: improve compatibility with Resolume products
Emma Worley
emma at emma.gg
Mon Apr 21 00:03:51 EEST 2025
Improves compatibility with Resolume products by adding an additional hashtable
for DXT color+LUT combinations, and padding the DXT texture to the next largest
16x16 multiple. Produces identical packets to Resolume Alley in manual tests.
Signed-off-by: Emma Worley <emma at emma.gg>
---
libavcodec/dxvenc.c | 89 +++++++++++++++++++------------------
tests/ref/fate/dxv3enc-dxt1 | 2 +-
2 files changed, 46 insertions(+), 45 deletions(-)
diff --git a/libavcodec/dxvenc.c b/libavcodec/dxvenc.c
index c64b4d5f15..b2972435a2 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_PAD(x) (x + 15 & ~15)
+
/*
* 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 AVHashtableContext *color_ht;
struct AVHashtableContext *lut_ht;
+ struct AVHashtableContext *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;
av_hashtable_clear(ctx->color_ht);
av_hashtable_clear(ctx->lut_ht);
+ av_hashtable_clear(ctx->combo_ht);
+
+ av_hashtable_set(ctx->combo_ht, ctx->tex_data, &pos);
bytestream2_put_le32(pbc, AV_RL32(ctx->tex_data));
av_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 = av_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 (av_hashtable_get(ctx->combo_ht, ctx->tex_data + old_pos * 4, &prev_pos) && prev_pos <= old_pos)
+ av_hashtable_delete(ctx->combo_ht, ctx->tex_data + old_pos * 4);
+ }
+ av_hashtable_set(ctx->combo_ht, &combo, &pos);
color = AV_RL32(ctx->tex_data + pos * 4);
- if (av_hashtable_get(ctx->color_ht, &color, &prev_pos))
- color_idx = pos - prev_pos;
- av_hashtable_set(ctx->color_ht, &color, &pos);
-
+ if (!combo_idx) {
+ idx = av_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 (av_hashtable_get(ctx->color_ht, ctx->tex_data + old_pos * 4, &prev_pos) && prev_pos <= old_pos)
av_hashtable_delete(ctx->color_ht, ctx->tex_data + old_pos * 4);
}
+ av_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 (av_hashtable_get(ctx->lut_ht, &lut, &prev_pos))
- lut_idx = pos - prev_pos;
- av_hashtable_set(ctx->lut_ht, &lut, &pos);
+ if (!combo_idx) {
+ idx = av_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 (av_hashtable_get(ctx->lut_ht, ctx->tex_data + old_pos * 4, &prev_pos) && prev_pos <= old_pos)
av_hashtable_delete(ctx->lut_ht, ctx->tex_data + old_pos * 4);
}
+ av_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;
@@ -175,8 +180,8 @@ static int dxv_encode(AVCodecContext *avctx, AVPacket *pkt,
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.width = DXV_PAD(avctx->width);
+ ctx->enc.height = DXV_PAD(avctx->height);
ff_texturedsp_exec_compress_threads(avctx, &ctx->enc);
} else {
/* unimplemented: YCoCg formats */
@@ -216,14 +221,6 @@ 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 +234,10 @@ 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_PAD(avctx->width) / TEXTURE_BLOCK_W *
+ DXV_PAD(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_PAD(avctx->height) / TEXTURE_BLOCK_H);
ctx->tex_data = av_malloc(ctx->tex_size);
if (!ctx->tex_data) {
@@ -251,6 +248,9 @@ static av_cold int dxv_init(AVCodecContext *avctx)
if (ret < 0)
return ret;
ret = av_hashtable_alloc(&ctx->lut_ht, sizeof(uint32_t), sizeof(uint32_t), LOOKBACK_HT_ELEMS);
+ if (ret < 0)
+ return ret;
+ ret = av_hashtable_alloc(&ctx->combo_ht, sizeof(uint64_t), sizeof(uint32_t), LOOKBACK_HT_ELEMS);
if (ret < 0)
return ret;
@@ -265,6 +265,7 @@ static av_cold int dxv_close(AVCodecContext *avctx)
av_hashtable_freep(&ctx->color_ht);
av_hashtable_freep(&ctx->lut_ht);
+ av_hashtable_freep(&ctx->combo_ht);
return 0;
}
diff --git a/tests/ref/fate/dxv3enc-dxt1 b/tests/ref/fate/dxv3enc-dxt1
index 74849a8031..1e1b86aa6c 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, 76563, 0x6b028fff
--
2.48.0
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