ffmpeg/libavcodec/dxvenc.c

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/*
* 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/opt.h"
#include "bytestream.h"
#include "codec_internal.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
enum DXVTextureFormat {
DXV_FMT_DXT1 = MKBETAG('D', 'X', 'T', '1'),
};
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;
TextureDSPContext texdsp;
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;
enum 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;
static int compress_texture_thread(AVCodecContext *avctx, void *arg,
int slice, int thread_nb)
{
DXVEncContext *ctx = avctx->priv_data;
AVFrame *frame = arg;
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];
return ff_texturedsp_compress_thread(avctx, &ctx->enc, slice, thread_nb);
} else {
/* unimplemented: YCoCg formats */
return AVERROR_INVALIDDATA;
}
return 0;
}
/* 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 = (uint32_t*)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; \
} \
*value |= (op << (state * 2)); \
state++; \
} while (0)
static int dxv_compress_dxt1(AVCodecContext *avctx)
{
DXVEncContext *ctx = avctx->priv_data;
PutByteContext *pbc = &ctx->pbc;
uint32_t *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;
avctx->execute2(avctx, compress_texture_thread, (void*)frame, NULL, ctx->enc.slice_count);
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;
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;
}
ff_texturedspenc_init(&ctx->texdsp);
switch (ctx->tex_fmt) {
case DXV_FMT_DXT1:
ctx->compress_tex = dxv_compress_dxt1;
ctx->enc.tex_funct = ctx->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 = FFALIGN(avctx->width, 16) / TEXTURE_BLOCK_W *
FFALIGN(avctx->height, 16) / TEXTURE_BLOCK_H *
ctx->enc.tex_ratio;
ctx->enc.slice_count = av_clip(avctx->thread_count, 1, FFALIGN(avctx->height, 16) / 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, "format" },
{ "dxt1", "DXT1 (Normal Quality, No Alpha)", 0, AV_OPT_TYPE_CONST, { .i64 = DXV_FMT_DXT1 }, 0, 0, FLAGS, "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,
};