libavcodec/dxvenc.c - third_party/ffmpeg - Git at Google

 /*
  * Resolume DXV encoder
  * Copyright (C) 2024 Connor Worley <connorbworley@gmail.com>
  *
  * This file is part of FFmpeg.
  *
  * FFmpeg is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *
  * FFmpeg is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
  * License along with FFmpeg; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */

 #include <stdint.h>

 #include "libavutil/crc.h"
 #include "libavutil/imgutils.h"
 #include "libavutil/mem.h"
 #include "libavutil/opt.h"

 #include "bytestream.h"
 #include "codec_internal.h"
 #include "dxv.h"
 #include "encode.h"
 #include "texturedsp.h"

 #define DXV_HEADER_LENGTH 12

 /*
  * DXV uses LZ-like back-references to avoid copying words that have already
  * appeared in the decompressed stream. Using a simple hash table (HT)
  * significantly speeds up the lookback process while encoding.
  */
 #define LOOKBACK_HT_ELEMS 0x40000
 #define LOOKBACK_WORDS    0x20202

 typedef struct HTEntry {
     uint32_t key;
     uint32_t pos;
 } HTEntry;

 static void ht_init(HTEntry *ht)
 {
     for (size_t i = 0; i < LOOKBACK_HT_ELEMS; i++) {
         ht[i].pos = -1;
     }
 }

 static uint32_t ht_lookup_and_upsert(HTEntry *ht, const AVCRC *hash_ctx,
                                     uint32_t key, uint32_t pos)
 {
     uint32_t ret = -1;
     size_t hash = av_crc(hash_ctx, 0, (uint8_t*)&key, 4) % LOOKBACK_HT_ELEMS;
     for (size_t i = hash; i < hash + LOOKBACK_HT_ELEMS; i++) {
         size_t wrapped_index = i % LOOKBACK_HT_ELEMS;
         HTEntry *entry = &ht[wrapped_index];
         if (entry->key == key || entry->pos == -1) {
             ret = entry->pos;
             entry->key = key;
             entry->pos = pos;
             break;
         }
     }
     return ret;
 }

 static void ht_delete(HTEntry *ht, const AVCRC *hash_ctx,
                       uint32_t key, uint32_t pos)
 {
     HTEntry *removed_entry = NULL;
     size_t removed_hash;
     size_t hash = av_crc(hash_ctx, 0, (uint8_t*)&key, 4) % LOOKBACK_HT_ELEMS;

     for (size_t i = hash; i < hash + LOOKBACK_HT_ELEMS; i++) {
         size_t wrapped_index = i % LOOKBACK_HT_ELEMS;
         HTEntry *entry = &ht[wrapped_index];
         if (entry->pos == -1)
             return;
         if (removed_entry) {
             size_t candidate_hash = av_crc(hash_ctx, 0, (uint8_t*)&entry->key, 4) % LOOKBACK_HT_ELEMS;
             if ((wrapped_index > removed_hash && (candidate_hash <= removed_hash || candidate_hash > wrapped_index)) ||
                 (wrapped_index < removed_hash && (candidate_hash <= removed_hash && candidate_hash > wrapped_index))) {
                 *removed_entry = *entry;
                 entry->pos = -1;
                 removed_entry = entry;
                 removed_hash = wrapped_index;
             }
         } else if (entry->key == key) {
             if (entry->pos <= pos) {
                 entry->pos = -1;
                 removed_entry = entry;
                 removed_hash = wrapped_index;
             } else {
                 return;
             }
         }
     }
 }

 typedef struct DXVEncContext {
     AVClass *class;

     PutByteContext pbc;

     uint8_t *tex_data;   // Compressed texture
     int64_t tex_size;    // Texture size

     /* Optimal number of slices for parallel decoding */
     int slice_count;

     TextureDSPThreadContext enc;

     DXVTextureFormat tex_fmt;
     int (*compress_tex)(AVCodecContext *avctx);

     const AVCRC *crc_ctx;

     HTEntry color_lookback_ht[LOOKBACK_HT_ELEMS];
     HTEntry lut_lookback_ht[LOOKBACK_HT_ELEMS];
 } DXVEncContext;

 /* Converts an index offset value to a 2-bit opcode and pushes it to a stream.
  * Inverse of CHECKPOINT in dxv.c.  */
 #define PUSH_OP(x)                                                            \
     do {                                                                      \
         if (state == 16) {                                                    \
             if (bytestream2_get_bytes_left_p(pbc) < 4) {                      \
                 return AVERROR_INVALIDDATA;                                   \
             }                                                                 \
             value = pbc->buffer;                                              \
             bytestream2_put_le32(pbc, 0);                                     \
             state = 0;                                                        \
         }                                                                     \
         if (idx >= 0x102 * x) {                                               \
             op = 3;                                                           \
             bytestream2_put_le16(pbc, (idx / x) - 0x102);                     \
         } else if (idx >= 2 * x) {                                            \
             op = 2;                                                           \
             bytestream2_put_byte(pbc, (idx / x) - 2);                         \
         } else if (idx == x) {                                                \
             op = 1;                                                           \
         } else {                                                              \
             op = 0;                                                           \
         }                                                                     \
         AV_WL32(value, AV_RL32(value) | (op << (state * 2)));                 \
         state++;                                                              \
     } while (0)

 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 = 2, op = 0;

     ht_init(ctx->color_lookback_ht);
     ht_init(ctx->lut_lookback_ht);

     bytestream2_put_le32(pbc, AV_RL32(ctx->tex_data));
     bytestream2_put_le32(pbc, AV_RL32(ctx->tex_data + 4));

     ht_lookup_and_upsert(ctx->color_lookback_ht, ctx->crc_ctx, AV_RL32(ctx->tex_data), 0);
     ht_lookup_and_upsert(ctx->lut_lookback_ht, ctx->crc_ctx, AV_RL32(ctx->tex_data + 4), 1);

     while (pos + 2 <= ctx->tex_size / 4) {
         idx = 0;

         color = AV_RL32(ctx->tex_data + pos * 4);
         prev_pos = ht_lookup_and_upsert(ctx->color_lookback_ht, ctx->crc_ctx, color, pos);
         color_idx = prev_pos != -1 ? pos - prev_pos : 0;
         if (pos >= LOOKBACK_WORDS) {
             uint32_t old_pos = pos - LOOKBACK_WORDS;
             uint32_t old_color = AV_RL32(ctx->tex_data + old_pos * 4);
             ht_delete(ctx->color_lookback_ht, ctx->crc_ctx, old_color, old_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;
             prev_pos = ht_lookup_and_upsert(ctx->lut_lookback_ht, ctx->crc_ctx, lut, pos);
             lut_idx = prev_pos != -1 ? pos - prev_pos : 0;
         }
         if (pos >= LOOKBACK_WORDS) {
             uint32_t old_pos = pos - LOOKBACK_WORDS;
             uint32_t old_lut = AV_RL32(ctx->tex_data + old_pos * 4);
             ht_delete(ctx->lut_lookback_ht, ctx->crc_ctx, old_lut, old_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;
 }

 static int dxv_encode(AVCodecContext *avctx, AVPacket *pkt,
                       const AVFrame *frame, int *got_packet)
 {
     DXVEncContext *ctx = avctx->priv_data;
     PutByteContext *pbc = &ctx->pbc;
     int ret;

     /* unimplemented: needs to depend on compression ratio of tex format */
     /* under DXT1, we need 3 words to encode load ops for 32 words.
      * the first 2 words of the texture do not need load ops. */
     ret = ff_alloc_packet(avctx, pkt, DXV_HEADER_LENGTH + ctx->tex_size + AV_CEIL_RSHIFT(ctx->tex_size - 8, 7) * 12);
     if (ret < 0)
         return ret;

     if (ctx->enc.tex_funct) {
         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;
         ff_texturedsp_exec_compress_threads(avctx, &ctx->enc);
     } else {
         /* unimplemented: YCoCg formats */
         return AVERROR_INVALIDDATA;
     }

     bytestream2_init_writer(pbc, pkt->data, pkt->size);

     bytestream2_put_le32(pbc, ctx->tex_fmt);
     bytestream2_put_byte(pbc, 4);
     bytestream2_put_byte(pbc, 0);
     bytestream2_put_byte(pbc, 0);
     bytestream2_put_byte(pbc, 0);
     /* Fill in compressed size later */
     bytestream2_skip_p(pbc, 4);

     ret = ctx->compress_tex(avctx);
     if (ret < 0)
         return ret;

     AV_WL32(pkt->data + 8, bytestream2_tell_p(pbc) - DXV_HEADER_LENGTH);
     av_shrink_packet(pkt, bytestream2_tell_p(pbc));

     *got_packet = 1;
     return 0;
 }

 static av_cold int dxv_init(AVCodecContext *avctx)
 {
     DXVEncContext *ctx = avctx->priv_data;
     TextureDSPEncContext texdsp;
     int ret = av_image_check_size(avctx->width, avctx->height, 0, avctx);

     if (ret < 0) {
         av_log(avctx, AV_LOG_ERROR, "Invalid image size %dx%d.\n",
                avctx->width, avctx->height);
         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) {
     case DXV_FMT_DXT1:
         ctx->compress_tex = dxv_compress_dxt1;
         ctx->enc.tex_funct = texdsp.dxt1_block;
         ctx->enc.tex_ratio = 8;
         break;
     default:
         av_log(avctx, AV_LOG_ERROR, "Invalid format %08X\n", ctx->tex_fmt);
         return AVERROR_INVALIDDATA;
     }
     ctx->enc.raw_ratio = 16;
     ctx->tex_size = avctx->width  / TEXTURE_BLOCK_W *
                     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->tex_data = av_malloc(ctx->tex_size);
     if (!ctx->tex_data) {
         return AVERROR(ENOMEM);
     }

     ctx->crc_ctx = av_crc_get_table(AV_CRC_32_IEEE);
     if (!ctx->crc_ctx) {
         av_log(avctx, AV_LOG_ERROR, "Could not initialize CRC table.\n");
         return AVERROR_BUG;
     }

     return 0;
 }

 static av_cold int dxv_close(AVCodecContext *avctx)
 {
     DXVEncContext *ctx = avctx->priv_data;

     av_freep(&ctx->tex_data);

     return 0;
 }

 #define OFFSET(x) offsetof(DXVEncContext, x)
 #define FLAGS     AV_OPT_FLAG_VIDEO_PARAM | AV_OPT_FLAG_ENCODING_PARAM
 static const AVOption options[] = {
     { "format", NULL, OFFSET(tex_fmt), AV_OPT_TYPE_INT, { .i64 = DXV_FMT_DXT1 }, DXV_FMT_DXT1, DXV_FMT_DXT1, FLAGS, .unit = "format" },
         { "dxt1", "DXT1 (Normal Quality, No Alpha)", 0, AV_OPT_TYPE_CONST, { .i64 = DXV_FMT_DXT1   }, 0, 0, FLAGS, .unit = "format" },
     { NULL },
 };

 static const AVClass dxvenc_class = {
     .class_name = "DXV encoder",
     .option     = options,
     .version    = LIBAVUTIL_VERSION_INT,
 };

 const FFCodec ff_dxv_encoder = {
     .p.name         = "dxv",
     CODEC_LONG_NAME("Resolume DXV"),
     .p.type         = AVMEDIA_TYPE_VIDEO,
     .p.id           = AV_CODEC_ID_DXV,
     .init           = dxv_init,
     FF_CODEC_ENCODE_CB(dxv_encode),
     .close          = dxv_close,
     .priv_data_size = sizeof(DXVEncContext),
     .p.capabilities = AV_CODEC_CAP_DR1 |
                       AV_CODEC_CAP_SLICE_THREADS |
                       AV_CODEC_CAP_FRAME_THREADS,
     .p.priv_class   = &dxvenc_class,
     .p.pix_fmts     = (const enum AVPixelFormat[]) {
         AV_PIX_FMT_RGBA, AV_PIX_FMT_NONE,
     },
     .caps_internal  = FF_CODEC_CAP_INIT_CLEANUP,
 };
	/*
	* Resolume DXV encoder
	* Copyright (C) 2024 Connor Worley <connorbworley@gmail.com>
	*
	* This file is part of FFmpeg.
	*
	* FFmpeg is free software; you can redistribute it and/or
	* modify it under the terms of the GNU Lesser General Public
	* License as published by the Free Software Foundation; either
	* version 2.1 of the License, or (at your option) any later version.
	*
	* FFmpeg is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	* Lesser General Public License for more details.
	*
	* You should have received a copy of the GNU Lesser General Public
	* License along with FFmpeg; if not, write to the Free Software
	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
	*/

	#include <stdint.h>

	#include "libavutil/crc.h"
	#include "libavutil/imgutils.h"
	#include "libavutil/mem.h"
	#include "libavutil/opt.h"

	#include "bytestream.h"
	#include "codec_internal.h"
	#include "dxv.h"
	#include "encode.h"
	#include "texturedsp.h"

	#define DXV_HEADER_LENGTH 12

	/*
	* DXV uses LZ-like back-references to avoid copying words that have already
	* appeared in the decompressed stream. Using a simple hash table (HT)
	* significantly speeds up the lookback process while encoding.
	*/
	#define LOOKBACK_HT_ELEMS 0x40000
	#define LOOKBACK_WORDS 0x20202

	typedef struct HTEntry {
	uint32_t key;
	uint32_t pos;
	} HTEntry;

	static void ht_init(HTEntry *ht)
	{
	for (size_t i = 0; i < LOOKBACK_HT_ELEMS; i++) {
	ht[i].pos = -1;
	}
	}

	static uint32_t ht_lookup_and_upsert(HTEntry ht, const AVCRC hash_ctx,
	uint32_t key, uint32_t pos)
	{
	uint32_t ret = -1;
	size_t hash = av_crc(hash_ctx, 0, (uint8_t*)&key, 4) % LOOKBACK_HT_ELEMS;
	for (size_t i = hash; i < hash + LOOKBACK_HT_ELEMS; i++) {
	size_t wrapped_index = i % LOOKBACK_HT_ELEMS;
	HTEntry *entry = &ht[wrapped_index];
	if (entry->key == key \|\| entry->pos == -1) {
	ret = entry->pos;
	entry->key = key;
	entry->pos = pos;
	break;
	}
	}
	return ret;
	}

	static void ht_delete(HTEntry ht, const AVCRC hash_ctx,
	uint32_t key, uint32_t pos)
	{
	HTEntry *removed_entry = NULL;
	size_t removed_hash;
	size_t hash = av_crc(hash_ctx, 0, (uint8_t*)&key, 4) % LOOKBACK_HT_ELEMS;

	for (size_t i = hash; i < hash + LOOKBACK_HT_ELEMS; i++) {
	size_t wrapped_index = i % LOOKBACK_HT_ELEMS;
	HTEntry *entry = &ht[wrapped_index];
	if (entry->pos == -1)
	return;
	if (removed_entry) {
	size_t candidate_hash = av_crc(hash_ctx, 0, (uint8_t*)&entry->key, 4) % LOOKBACK_HT_ELEMS;
	if ((wrapped_index > removed_hash && (candidate_hash <= removed_hash \|\| candidate_hash > wrapped_index)) \|\|
	(wrapped_index < removed_hash && (candidate_hash <= removed_hash && candidate_hash > wrapped_index))) {
	removed_entry = entry;
	entry->pos = -1;
	removed_entry = entry;
	removed_hash = wrapped_index;
	}
	} else if (entry->key == key) {
	if (entry->pos <= pos) {
	entry->pos = -1;
	removed_entry = entry;
	removed_hash = wrapped_index;
	} else {
	return;
	}
	}
	}
	}

	typedef struct DXVEncContext {
	AVClass *class;

	PutByteContext pbc;

	uint8_t *tex_data; // Compressed texture
	int64_t tex_size; // Texture size

	/* Optimal number of slices for parallel decoding */
	int slice_count;

	TextureDSPThreadContext enc;

	DXVTextureFormat tex_fmt;
	int (compress_tex)(AVCodecContext avctx);

	const AVCRC *crc_ctx;

	HTEntry color_lookback_ht[LOOKBACK_HT_ELEMS];
	HTEntry lut_lookback_ht[LOOKBACK_HT_ELEMS];
	} DXVEncContext;

	/* Converts an index offset value to a 2-bit opcode and pushes it to a stream.
	* Inverse of CHECKPOINT in dxv.c. */
	#define PUSH_OP(x) \
	do { \
	if (state == 16) { \
	if (bytestream2_get_bytes_left_p(pbc) < 4) { \
	return AVERROR_INVALIDDATA; \
	} \
	value = pbc->buffer; \
	bytestream2_put_le32(pbc, 0); \
	state = 0; \
	} \
	if (idx >= 0x102 * x) { \
	op = 3; \
	bytestream2_put_le16(pbc, (idx / x) - 0x102); \
	} else if (idx >= 2 * x) { \
	op = 2; \
	bytestream2_put_byte(pbc, (idx / x) - 2); \
	} else if (idx == x) { \
	op = 1; \
	} else { \
	op = 0; \
	} \
	AV_WL32(value, AV_RL32(value) \| (op << (state * 2))); \
	state++; \
	} while (0)

	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 = 2, op = 0;

	ht_init(ctx->color_lookback_ht);
	ht_init(ctx->lut_lookback_ht);

	bytestream2_put_le32(pbc, AV_RL32(ctx->tex_data));
	bytestream2_put_le32(pbc, AV_RL32(ctx->tex_data + 4));

	ht_lookup_and_upsert(ctx->color_lookback_ht, ctx->crc_ctx, AV_RL32(ctx->tex_data), 0);
	ht_lookup_and_upsert(ctx->lut_lookback_ht, ctx->crc_ctx, AV_RL32(ctx->tex_data + 4), 1);

	while (pos + 2 <= ctx->tex_size / 4) {
	idx = 0;

	color = AV_RL32(ctx->tex_data + pos * 4);
	prev_pos = ht_lookup_and_upsert(ctx->color_lookback_ht, ctx->crc_ctx, color, pos);
	color_idx = prev_pos != -1 ? pos - prev_pos : 0;
	if (pos >= LOOKBACK_WORDS) {
	uint32_t old_pos = pos - LOOKBACK_WORDS;
	uint32_t old_color = AV_RL32(ctx->tex_data + old_pos * 4);
	ht_delete(ctx->color_lookback_ht, ctx->crc_ctx, old_color, old_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;
	prev_pos = ht_lookup_and_upsert(ctx->lut_lookback_ht, ctx->crc_ctx, lut, pos);
	lut_idx = prev_pos != -1 ? pos - prev_pos : 0;
	}
	if (pos >= LOOKBACK_WORDS) {
	uint32_t old_pos = pos - LOOKBACK_WORDS;
	uint32_t old_lut = AV_RL32(ctx->tex_data + old_pos * 4);
	ht_delete(ctx->lut_lookback_ht, ctx->crc_ctx, old_lut, old_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;
	}

	static int dxv_encode(AVCodecContext avctx, AVPacket pkt,
	const AVFrame frame, int got_packet)
	{
	DXVEncContext *ctx = avctx->priv_data;
	PutByteContext *pbc = &ctx->pbc;
	int ret;

	/* unimplemented: needs to depend on compression ratio of tex format */
	/* under DXT1, we need 3 words to encode load ops for 32 words.
	* the first 2 words of the texture do not need load ops. */
	ret = ff_alloc_packet(avctx, pkt, DXV_HEADER_LENGTH + ctx->tex_size + AV_CEIL_RSHIFT(ctx->tex_size - 8, 7) * 12);
	if (ret < 0)
	return ret;

	if (ctx->enc.tex_funct) {
	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;
	ff_texturedsp_exec_compress_threads(avctx, &ctx->enc);
	} else {
	/* unimplemented: YCoCg formats */
	return AVERROR_INVALIDDATA;
	}

	bytestream2_init_writer(pbc, pkt->data, pkt->size);

	bytestream2_put_le32(pbc, ctx->tex_fmt);
	bytestream2_put_byte(pbc, 4);
	bytestream2_put_byte(pbc, 0);
	bytestream2_put_byte(pbc, 0);
	bytestream2_put_byte(pbc, 0);
	/* Fill in compressed size later */
	bytestream2_skip_p(pbc, 4);

	ret = ctx->compress_tex(avctx);
	if (ret < 0)
	return ret;

	AV_WL32(pkt->data + 8, bytestream2_tell_p(pbc) - DXV_HEADER_LENGTH);
	av_shrink_packet(pkt, bytestream2_tell_p(pbc));

	*got_packet = 1;
	return 0;
	}

	static av_cold int dxv_init(AVCodecContext *avctx)
	{
	DXVEncContext *ctx = avctx->priv_data;
	TextureDSPEncContext texdsp;
	int ret = av_image_check_size(avctx->width, avctx->height, 0, avctx);

	if (ret < 0) {
	av_log(avctx, AV_LOG_ERROR, "Invalid image size %dx%d.\n",
	avctx->width, avctx->height);
	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) {
	case DXV_FMT_DXT1:
	ctx->compress_tex = dxv_compress_dxt1;
	ctx->enc.tex_funct = texdsp.dxt1_block;
	ctx->enc.tex_ratio = 8;
	break;
	default:
	av_log(avctx, AV_LOG_ERROR, "Invalid format %08X\n", ctx->tex_fmt);
	return AVERROR_INVALIDDATA;
	}
	ctx->enc.raw_ratio = 16;
	ctx->tex_size = avctx->width / TEXTURE_BLOCK_W *
	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->tex_data = av_malloc(ctx->tex_size);
	if (!ctx->tex_data) {
	return AVERROR(ENOMEM);
	}

	ctx->crc_ctx = av_crc_get_table(AV_CRC_32_IEEE);
	if (!ctx->crc_ctx) {
	av_log(avctx, AV_LOG_ERROR, "Could not initialize CRC table.\n");
	return AVERROR_BUG;
	}

	return 0;
	}

	static av_cold int dxv_close(AVCodecContext *avctx)
	{
	DXVEncContext *ctx = avctx->priv_data;

	av_freep(&ctx->tex_data);

	return 0;
	}

	#define OFFSET(x) offsetof(DXVEncContext, x)
	#define FLAGS AV_OPT_FLAG_VIDEO_PARAM \| AV_OPT_FLAG_ENCODING_PARAM
	static const AVOption options[] = {
	{ "format", NULL, OFFSET(tex_fmt), AV_OPT_TYPE_INT, { .i64 = DXV_FMT_DXT1 }, DXV_FMT_DXT1, DXV_FMT_DXT1, FLAGS, .unit = "format" },
	{ "dxt1", "DXT1 (Normal Quality, No Alpha)", 0, AV_OPT_TYPE_CONST, { .i64 = DXV_FMT_DXT1 }, 0, 0, FLAGS, .unit = "format" },
	{ NULL },
	};

	static const AVClass dxvenc_class = {
	.class_name = "DXV encoder",
	.option = options,
	.version = LIBAVUTIL_VERSION_INT,
	};

	const FFCodec ff_dxv_encoder = {
	.p.name = "dxv",
	CODEC_LONG_NAME("Resolume DXV"),
	.p.type = AVMEDIA_TYPE_VIDEO,
	.p.id = AV_CODEC_ID_DXV,
	.init = dxv_init,
	FF_CODEC_ENCODE_CB(dxv_encode),
	.close = dxv_close,
	.priv_data_size = sizeof(DXVEncContext),
	.p.capabilities = AV_CODEC_CAP_DR1 \|
	AV_CODEC_CAP_SLICE_THREADS \|
	AV_CODEC_CAP_FRAME_THREADS,
	.p.priv_class = &dxvenc_class,
	.p.pix_fmts = (const enum AVPixelFormat[]) {
	AV_PIX_FMT_RGBA, AV_PIX_FMT_NONE,
	},
	.caps_internal = FF_CODEC_CAP_INIT_CLEANUP,
	};