/*
* Vidvox Hap decoder
* Copyright (C) 2015 Vittorio Giovara <vittorio.giovara@gmail.com>
* Copyright (C) 2015 Tom Butterworth <bangnoise@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
*/
/**
* @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 "memory.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(GetByteContext *gbc, int *section_size,
enum HapSectionType *section_type)
{
if (bytestream2_get_bytes_left(gbc) < 4)
return AVERROR_INVALIDDATA;
*section_size = bytestream2_get_le24(gbc);
*section_type = bytestream2_get_byte(gbc);
if (*section_size == 0) {
if (bytestream2_get_bytes_left(gbc) < 4)
return AVERROR_INVALIDDATA;
*section_size = bytestream2_get_le32(gbc);
}
if (*section_size > bytestream2_get_bytes_left(gbc) || *section_size < 0)
return AVERROR_INVALIDDATA;
else
return 0;
}
static int hap_parse_decode_instructions(HapContext *ctx, int size)
{
GetByteContext *gbc = &ctx->gbc;
int section_size;
enum HapSectionType section_type;
int is_first_table = 1, had_offsets = 0, had_compressors = 0, had_sizes = 0;
int i, ret;
while (size > 0) {
int stream_remaining = bytestream2_get_bytes_left(gbc);
ret = parse_section_header(gbc, §ion_size, §ion_type);
if (ret != 0)
return ret;
size -= stream_remaining - bytestream2_get_bytes_left(gbc);
switch (section_type) {
case HAP_ST_COMPRESSOR_TABLE:
ret = ff_hap_set_chunk_count(ctx, section_size, is_first_table);
if (ret != 0)
return ret;
for (i = 0; i < section_size; i++) {
ctx->chunks[i].compressor = bytestream2_get_byte(gbc) << 4;
}
had_compressors = 1;
is_first_table = 0;
break;
case HAP_ST_SIZE_TABLE:
ret = ff_hap_set_chunk_count(ctx, section_size / 4, is_first_table);
if (ret != 0)
return ret;
for (i = 0; i < section_size / 4; i++) {
ctx->chunks[i].compressed_size = bytestream2_get_le32(gbc);
}
had_sizes = 1;
is_first_table = 0;
break;
case HAP_ST_OFFSET_TABLE:
ret = ff_hap_set_chunk_count(ctx, section_size / 4, is_first_table);
if (ret != 0)
return ret;
for (i = 0; i < section_size / 4; i++) {
ctx->chunks[i].compressed_offset = bytestream2_get_le32(gbc);
}
had_offsets = 1;
is_first_table = 0;
break;
default:
break;
}
size -= section_size;
}
if (!had_sizes || !had_compressors)
return AVERROR_INVALIDDATA;
/* The offsets table is optional. If not present than calculate offsets by
* summing the sizes of preceding chunks. */
if (!had_offsets) {
size_t running_size = 0;
for (i = 0; i < ctx->chunk_count; i++) {
ctx->chunks[i].compressed_offset = running_size;
running_size += ctx->chunks[i].compressed_size;
}
}
return 0;
}
static int hap_can_use_tex_in_place(HapContext *ctx)
{
int i;
size_t running_offset = 0;
for (i = 0; i < ctx->chunk_count; i++) {
if (ctx->chunks[i].compressed_offset != running_offset
|| ctx->chunks[i].compressor != HAP_COMP_NONE)
return 0;
running_offset += ctx->chunks[i].compressed_size;
}
return 1;
}
static int hap_parse_frame_header(AVCodecContext *avctx)
{
HapContext *ctx = avctx->priv_data;
GetByteContext *gbc = &ctx->gbc;
int section_size;
enum HapSectionType section_type;
const char *compressorstr;
int i, ret;
ret = parse_section_header(gbc, §ion_size, §ion_type);
if (ret != 0)
return ret;
if ((avctx->codec_tag == MKTAG('H','a','p','1') && (section_type & 0x0F) != HAP_FMT_RGBDXT1) ||
(avctx->codec_tag == MKTAG('H','a','p','5') && (section_type & 0x0F) != HAP_FMT_RGBADXT5) ||
(avctx->codec_tag == MKTAG('H','a','p','Y') && (section_type & 0x0F) != HAP_FMT_YCOCGDXT5)) {
av_log(avctx, AV_LOG_ERROR,
"Invalid texture format %#04x.\n", section_type & 0x0F);
return AVERROR_INVALIDDATA;
}
switch (section_type & 0xF0) {
case HAP_COMP_NONE:
case HAP_COMP_SNAPPY:
ret = ff_hap_set_chunk_count(ctx, 1, 1);
if (ret == 0) {
ctx->chunks[0].compressor = section_type & 0xF0;
ctx->chunks[0].compressed_offset = 0;
ctx->chunks[0].compressed_size = section_size;
}
if (ctx->chunks[0].compressor == HAP_COMP_NONE) {
compressorstr = "none";
} else {
compressorstr = "snappy";
}
break;
case HAP_COMP_COMPLEX:
ret = parse_section_header(gbc, §ion_size, §ion_type);
if (ret == 0 && section_type != HAP_ST_DECODE_INSTRUCTIONS)
ret = AVERROR_INVALIDDATA;
if (ret == 0)
ret = hap_parse_decode_instructions(ctx, section_size);
compressorstr = "complex";
break;
default:
ret = AVERROR_INVALIDDATA;
break;
}
if (ret != 0)
return ret;
/* Check the frame is valid and read the uncompressed chunk sizes */
ctx->tex_size = 0;
for (i = 0; i < ctx->chunk_count; i++) {
HapChunk *chunk = &ctx->chunks[i];
/* Check the compressed buffer is valid */
if (chunk->compressed_offset + chunk->compressed_size > bytestream2_get_bytes_left(gbc))
return AVERROR_INVALIDDATA;
/* Chunks are unpacked sequentially, ctx->tex_size is the uncompressed
* size thus far */
chunk->uncompressed_offset = ctx->tex_size;
/* Fill out uncompressed size */
if (chunk->compressor == HAP_COMP_SNAPPY) {
GetByteContext gbc_tmp;
int64_t uncompressed_size;
bytestream2_init(&gbc_tmp, gbc->buffer + chunk->compressed_offset,
chunk->compressed_size);
uncompressed_size = ff_snappy_peek_uncompressed_length(&gbc_tmp);
if (uncompressed_size < 0) {
return uncompressed_size;
}
chunk->uncompressed_size = uncompressed_size;
} else if (chunk->compressor == HAP_COMP_NONE) {
chunk->uncompressed_size = chunk->compressed_size;
} else {
return AVERROR_INVALIDDATA;
}
ctx->tex_size += chunk->uncompressed_size;
}
av_log(avctx, AV_LOG_DEBUG, "%s compressor\n", compressorstr);
return ret;
}
static int decompress_chunks_thread(AVCodecContext *avctx, void *arg,
int chunk_nb, int thread_nb)
{
HapContext *ctx = avctx->priv_data;
HapChunk *chunk = &ctx->chunks[chunk_nb];
GetByteContext gbc;
uint8_t *dst = ctx->tex_buf + chunk->uncompressed_offset;
bytestream2_init(&gbc, ctx->gbc.buffer + chunk->compressed_offset, chunk->compressed_size);
if (chunk->compressor == HAP_COMP_SNAPPY) {
int ret;
int64_t uncompressed_size = ctx->tex_size;
/* Uncompress the frame */
ret = ff_snappy_uncompress(&gbc, dst, &uncompressed_size);
if (ret < 0) {
av_log(avctx, AV_LOG_ERROR, "Snappy uncompress error\n");
return ret;
}
} else if (chunk->compressor == HAP_COMP_NONE) {
bytestream2_get_buffer(&gbc, dst, chunk->compressed_size);
}
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, i;
int tex_size;
bytestream2_init(&ctx->gbc, avpkt->data, avpkt->size);
/* Check for section header */
ret = hap_parse_frame_header(avctx);
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;
if (avctx->codec->update_thread_context)
ff_thread_finish_setup(avctx);
/* Unpack the DXT texture */
if (hap_can_use_tex_in_place(ctx)) {
/* Only DXTC texture compression in a contiguous block */
ctx->tex_data = ctx->gbc.buffer;
tex_size = bytestream2_get_bytes_left(&ctx->gbc);
} else {
/* Perform the second-stage decompression */
ret = av_reallocp(&ctx->tex_buf, ctx->tex_size);
if (ret < 0)
return ret;
avctx->execute2(avctx, decompress_chunks_thread, NULL,
ctx->chunk_results, ctx->chunk_count);
for (i = 0; i < ctx->chunk_count; i++) {
if (ctx->chunk_results[i] < 0)
return ctx->chunk_results[i];
}
ctx->tex_data = ctx->tex_buf;
tex_size = ctx->tex_size;
}
if (tex_size < (avctx->coded_width / TEXTURE_BLOCK_W)
*(avctx->coded_height / TEXTURE_BLOCK_H)
*ctx->tex_rat) {
av_log(avctx, AV_LOG_ERROR, "Insufficient data\n");
return AVERROR_INVALIDDATA;
}
/* 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;
ff_hap_free_context(ctx);
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,
};