ffmpeg/libavcodec/hapdec.c

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/*
* Vidvox Hap decoder
* Copyright (C) 2015 Vittorio Giovara <vittorio.giovara@gmail.com>
*
* This file is part of Libav.
*
* Libav 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.
*
* Libav 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 Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* Hap decoder
*
* Fourcc: Hap1, Hap5, HapY
*
* https://github.com/Vidvox/hap/blob/master/documentation/HapVideoDRAFT.md
*/
#include <stdint.h>
#include "libavutil/imgutils.h"
#include "avcodec.h"
#include "bytestream.h"
#include "hap.h"
#include "internal.h"
#include "snappy.h"
#include "texturedsp.h"
#include "thread.h"
/* The first three bytes are the size of the section past the header, or zero
* if the length is stored in the next long word. The fourth byte in the first
* long word indicates the type of the current section. */
static int parse_section_header(AVCodecContext *avctx)
{
HapContext *ctx = avctx->priv_data;
GetByteContext *gbc = &ctx->gbc;
int length;
if (bytestream2_get_bytes_left(gbc) < 4)
return AVERROR_INVALIDDATA;
length = bytestream2_get_le24(gbc);
ctx->section_type = bytestream2_get_byte(gbc);
if (length == 0) {
if (bytestream2_get_bytes_left(gbc) < 4)
return AVERROR_INVALIDDATA;
length = bytestream2_get_le32(gbc);
}
if (length > bytestream2_get_bytes_left(gbc) || length == 0)
return AVERROR_INVALIDDATA;
return length;
}
/* Prepare the texture to be decompressed */
static int setup_texture(AVCodecContext *avctx, size_t length)
{
HapContext *ctx = avctx->priv_data;
GetByteContext *gbc = &ctx->gbc;
int64_t snappy_size;
const char *compressorstr;
int ret;
if ((avctx->codec_tag == MKTAG('H','a','p','1') && (ctx->section_type & 0x0F) != HAP_FMT_RGBDXT1) ||
(avctx->codec_tag == MKTAG('H','a','p','5') && (ctx->section_type & 0x0F) != HAP_FMT_RGBADXT5) ||
(avctx->codec_tag == MKTAG('H','a','p','Y') && (ctx->section_type & 0x0F) != HAP_FMT_YCOCGDXT5)) {
av_log(avctx, AV_LOG_ERROR,
"Invalid texture format %#04x.\n", ctx->section_type & 0x0F);
return AVERROR_INVALIDDATA;
}
switch (ctx->section_type & 0xF0) {
case HAP_COMP_NONE:
/* Only DXTC texture compression */
ctx->tex_data = gbc->buffer;
ctx->tex_size = length;
compressorstr = "none";
break;
case HAP_COMP_SNAPPY:
snappy_size = ff_snappy_peek_uncompressed_length(gbc);
ret = av_reallocp(&ctx->snappied, snappy_size);
if (ret < 0) {
return ret;
}
/* Uncompress the frame */
ret = ff_snappy_uncompress(gbc, ctx->snappied, &snappy_size);
if (ret < 0) {
av_log(avctx, AV_LOG_ERROR, "Snappy uncompress error\n");
return ret;
}
ctx->tex_data = ctx->snappied;
ctx->tex_size = snappy_size;
compressorstr = "snappy";
break;
case HAP_COMP_COMPLEX:
compressorstr = "complex";
avpriv_request_sample(avctx, "Complex Hap compressor");
return AVERROR_PATCHWELCOME;
break;
default:
av_log(avctx, AV_LOG_ERROR,
"Invalid compressor mode %02X.\n", ctx->section_type);
return AVERROR_INVALIDDATA;
}
av_log(avctx, AV_LOG_DEBUG, "%s compressor\n", compressorstr);
return 0;
}
static int decompress_texture_thread(AVCodecContext *avctx, void *arg,
int slice, int thread_nb)
{
HapContext *ctx = avctx->priv_data;
AVFrame *frame = arg;
const uint8_t *d = ctx->tex_data;
int w_block = avctx->coded_width / TEXTURE_BLOCK_W;
int h_block = avctx->coded_height / TEXTURE_BLOCK_H;
int x, y;
int start_slice, end_slice;
int base_blocks_per_slice = h_block / ctx->slice_count;
int remainder_blocks = h_block % ctx->slice_count;
/* When the frame height (in blocks) doesn't divide evenly between the
* number of slices, spread the remaining blocks evenly between the first
* operations */
start_slice = slice * base_blocks_per_slice;
/* Add any extra blocks (one per slice) that have been added before this slice */
start_slice += FFMIN(slice, remainder_blocks);
end_slice = start_slice + base_blocks_per_slice;
/* Add an extra block if there are still remainder blocks to be accounted for */
if (slice < remainder_blocks)
end_slice++;
for (y = start_slice; y < end_slice; y++) {
uint8_t *p = frame->data[0] + y * frame->linesize[0] * TEXTURE_BLOCK_H;
int off = y * w_block;
for (x = 0; x < w_block; x++) {
ctx->tex_fun(p + x * 16, frame->linesize[0],
d + (off + x) * ctx->tex_rat);
}
}
return 0;
}
static int hap_decode(AVCodecContext *avctx, void *data,
int *got_frame, AVPacket *avpkt)
{
HapContext *ctx = avctx->priv_data;
ThreadFrame tframe;
int ret, length;
bytestream2_init(&ctx->gbc, avpkt->data, avpkt->size);
/* Check for section header */
length = parse_section_header(avctx);
if (length < 0) {
av_log(avctx, AV_LOG_ERROR, "Frame is too small.\n");
return length;
}
/* Prepare the texture buffer and decompress function */
ret = setup_texture(avctx, length);
if (ret < 0)
return ret;
/* Get the output frame ready to receive data */
tframe.f = data;
ret = ff_thread_get_buffer(avctx, &tframe, 0);
if (ret < 0)
return ret;
ff_thread_finish_setup(avctx);
/* Use the decompress function on the texture, one block per thread */
avctx->execute2(avctx, decompress_texture_thread, tframe.f, NULL, ctx->slice_count);
/* Frame is ready to be output */
tframe.f->pict_type = AV_PICTURE_TYPE_I;
tframe.f->key_frame = 1;
*got_frame = 1;
return avpkt->size;
}
static av_cold int hap_init(AVCodecContext *avctx)
{
HapContext *ctx = avctx->priv_data;
const char *texture_name;
int ret = av_image_check_size(avctx->width, avctx->height, 0, avctx);
if (ret < 0) {
av_log(avctx, AV_LOG_ERROR, "Invalid video size %dx%d.\n",
avctx->width, avctx->height);
return ret;
}
/* Since codec is based on 4x4 blocks, size is aligned to 4 */
avctx->coded_width = FFALIGN(avctx->width, TEXTURE_BLOCK_W);
avctx->coded_height = FFALIGN(avctx->height, TEXTURE_BLOCK_H);
/* Technically only one mode has alpha, but 32 bits are easier to handle */
avctx->pix_fmt = AV_PIX_FMT_RGBA;
ff_texturedsp_init(&ctx->dxtc);
switch (avctx->codec_tag) {
case MKTAG('H','a','p','1'):
texture_name = "DXT1";
ctx->tex_rat = 8;
ctx->tex_fun = ctx->dxtc.dxt1_block;
break;
case MKTAG('H','a','p','5'):
texture_name = "DXT5";
ctx->tex_rat = 16;
ctx->tex_fun = ctx->dxtc.dxt5_block;
break;
case MKTAG('H','a','p','Y'):
texture_name = "DXT5-YCoCg-scaled";
ctx->tex_rat = 16;
ctx->tex_fun = ctx->dxtc.dxt5ys_block;
break;
default:
return AVERROR_DECODER_NOT_FOUND;
}
av_log(avctx, AV_LOG_DEBUG, "%s texture\n", texture_name);
ctx->slice_count = av_clip(avctx->thread_count, 1,
avctx->coded_height / TEXTURE_BLOCK_H);
return 0;
}
static av_cold int hap_close(AVCodecContext *avctx)
{
HapContext *ctx = avctx->priv_data;
av_freep(&ctx->snappied);
return 0;
}
AVCodec ff_hap_decoder = {
.name = "hap",
.long_name = NULL_IF_CONFIG_SMALL("Vidvox Hap decoder"),
.type = AVMEDIA_TYPE_VIDEO,
.id = AV_CODEC_ID_HAP,
.init = hap_init,
.decode = hap_decode,
.close = hap_close,
.priv_data_size = sizeof(HapContext),
.capabilities = AV_CODEC_CAP_FRAME_THREADS | AV_CODEC_CAP_SLICE_THREADS |
AV_CODEC_CAP_DR1,
.caps_internal = FF_CODEC_CAP_INIT_THREADSAFE |
FF_CODEC_CAP_INIT_CLEANUP,
};