mirror of https://git.ffmpeg.org/ffmpeg.git
320 lines
9.9 KiB
C
320 lines
9.9 KiB
C
/*
|
|
* Escape 130 Video Decoder
|
|
* Copyright (C) 2008 Eli Friedman (eli.friedman <at> 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 "avcodec.h"
|
|
|
|
#define ALT_BITSTREAM_READER_LE
|
|
#include "get_bits.h"
|
|
|
|
typedef struct Escape130Context {
|
|
AVFrame frame;
|
|
uint8_t *bases;
|
|
} Escape130Context;
|
|
|
|
/**
|
|
* Initialize the decoder
|
|
* @param avctx decoder context
|
|
* @return 0 success, negative on error
|
|
*/
|
|
static av_cold int escape130_decode_init(AVCodecContext *avctx)
|
|
{
|
|
Escape130Context *s = avctx->priv_data;
|
|
avctx->pix_fmt = PIX_FMT_YUV420P;
|
|
|
|
if((avctx->width&1) || (avctx->height&1)){
|
|
av_log(avctx, AV_LOG_ERROR, "Dimensions are not a multiple of the block size\n");
|
|
return AVERROR(EINVAL);
|
|
}
|
|
|
|
s->bases= av_malloc(avctx->width * avctx->height /4);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static av_cold int escape130_decode_close(AVCodecContext *avctx)
|
|
{
|
|
Escape130Context *s = avctx->priv_data;
|
|
|
|
if (s->frame.data[0])
|
|
avctx->release_buffer(avctx, &s->frame);
|
|
|
|
av_freep(&s->bases);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static unsigned decode_skip_count(GetBitContext* gb) {
|
|
unsigned value;
|
|
// This function reads a maximum of 27 bits,
|
|
// which is within the padding space
|
|
if (get_bits_left(gb) < 1+3)
|
|
return -1;
|
|
|
|
value = get_bits1(gb);
|
|
if (value)
|
|
return 0;
|
|
|
|
value = get_bits(gb, 3);
|
|
if (value)
|
|
return value;
|
|
|
|
value = get_bits(gb, 8);
|
|
if (value)
|
|
return value + 7;
|
|
|
|
value = get_bits(gb, 15);
|
|
if (value)
|
|
return value + 262;
|
|
|
|
return -1;
|
|
}
|
|
|
|
/**
|
|
* Decode a single frame
|
|
* @param avctx decoder context
|
|
* @param data decoded frame
|
|
* @param data_size size of the decoded frame
|
|
* @param buf input buffer
|
|
* @param buf_size input buffer size
|
|
* @return 0 success, -1 on error
|
|
*/
|
|
static int escape130_decode_frame(AVCodecContext *avctx,
|
|
void *data, int *data_size,
|
|
AVPacket *avpkt)
|
|
{
|
|
const uint8_t *buf = avpkt->data;
|
|
int buf_size = avpkt->size;
|
|
Escape130Context *s = avctx->priv_data;
|
|
|
|
GetBitContext gb;
|
|
unsigned i;
|
|
|
|
uint8_t *old_y, *old_cb, *old_cr,
|
|
*new_y, *new_cb, *new_cr;
|
|
unsigned old_y_stride, old_cb_stride, old_cr_stride,
|
|
new_y_stride, new_cb_stride, new_cr_stride;
|
|
unsigned total_blocks = avctx->width * avctx->height / 4,
|
|
block_index, row_index = 0;
|
|
unsigned y[4] = {0}, cb = 16, cr = 16;
|
|
unsigned skip = -1;
|
|
unsigned y_base = 0;
|
|
uint8_t *yb= s->bases;
|
|
|
|
AVFrame new_frame = { { 0 } };
|
|
|
|
init_get_bits(&gb, buf, buf_size * 8);
|
|
|
|
if (get_bits_left(&gb) < 128)
|
|
return -1;
|
|
|
|
// Header; no useful information in here
|
|
skip_bits_long(&gb, 128);
|
|
|
|
new_frame.reference = 3;
|
|
if (avctx->get_buffer(avctx, &new_frame)) {
|
|
av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
|
|
return -1;
|
|
}
|
|
|
|
new_y = new_frame.data[0];
|
|
new_cb = new_frame.data[1];
|
|
new_cr = new_frame.data[2];
|
|
new_y_stride = new_frame.linesize[0];
|
|
new_cb_stride = new_frame.linesize[1];
|
|
new_cr_stride = new_frame.linesize[2];
|
|
old_y = s->frame.data[0];
|
|
old_cb = s->frame.data[1];
|
|
old_cr = s->frame.data[2];
|
|
old_y_stride = s->frame.linesize[0];
|
|
old_cb_stride = s->frame.linesize[1];
|
|
old_cr_stride = s->frame.linesize[2];
|
|
|
|
av_log(avctx, AV_LOG_DEBUG,
|
|
"Strides: %i, %i\n",
|
|
new_y_stride, new_cb_stride);
|
|
|
|
for (block_index = 0; block_index < total_blocks; block_index++) {
|
|
// Note that this call will make us skip the rest of the blocks
|
|
// if the frame prematurely ends
|
|
if (skip == -1)
|
|
skip = decode_skip_count(&gb);
|
|
|
|
if (skip) {
|
|
if (old_y) {
|
|
y[0] = old_y[0] / 4;
|
|
y[1] = old_y[1] / 4;
|
|
y[2] = old_y[old_y_stride] / 4;
|
|
y[3] = old_y[old_y_stride+1] / 4;
|
|
y_base= yb[0];
|
|
cb = old_cb[0] / 8;
|
|
cr = old_cr[0] / 8;
|
|
} else {
|
|
y_base=y[0] = y[1] = y[2] = y[3] = 0;
|
|
cb = cr = 16;
|
|
}
|
|
} else {
|
|
if (get_bits1(&gb)) {
|
|
static const uint8_t offset_table[] = {2, 4, 10, 20};
|
|
static const int8_t sign_table[64][4] =
|
|
{ {0, 0, 0, 0},
|
|
{-1, 1, 0, 0},
|
|
{1, -1, 0, 0},
|
|
{-1, 0, 1, 0},
|
|
{-1, 1, 1, 0},
|
|
{0, -1, 1, 0},
|
|
{1, -1, 1, 0},
|
|
{-1, -1, 1, 0},
|
|
{1, 0, -1, 0},
|
|
{0, 1, -1, 0},
|
|
{1, 1, -1, 0},
|
|
{-1, 1, -1, 0},
|
|
{1, -1, -1, 0},
|
|
{-1, 0, 0, 1},
|
|
{-1, 1, 0, 1},
|
|
{0, -1, 0, 1},
|
|
|
|
{0, 0, 0, 0},
|
|
{1, -1, 0, 1},
|
|
{-1, -1, 0, 1},
|
|
{-1, 0, 1, 1},
|
|
{-1, 1, 1, 1},
|
|
{0, -1, 1, 1},
|
|
{1, -1, 1, 1},
|
|
{-1, -1, 1, 1},
|
|
{0, 0, -1, 1},
|
|
{1, 0, -1, 1},
|
|
{-1, 0, -1, 1},
|
|
{0, 1, -1, 1},
|
|
{1, 1, -1, 1},
|
|
{-1, 1, -1, 1},
|
|
{0, -1, -1, 1},
|
|
{1, -1, -1, 1},
|
|
|
|
{0, 0, 0, 0},
|
|
{-1, -1, -1, 1},
|
|
{1, 0, 0, -1},
|
|
{0, 1, 0, -1},
|
|
{1, 1, 0, -1},
|
|
{-1, 1, 0, -1},
|
|
{1, -1, 0, -1},
|
|
{0, 0, 1, -1},
|
|
{1, 0, 1, -1},
|
|
{-1, 0, 1, -1},
|
|
{0, 1, 1, -1},
|
|
{1, 1, 1, -1},
|
|
{-1, 1, 1, -1},
|
|
{0, -1, 1, -1},
|
|
{1, -1, 1, -1},
|
|
{-1, -1, 1, -1},
|
|
|
|
{0, 0, 0, 0},
|
|
{1, 0, -1, -1},
|
|
{0, 1, -1, -1},
|
|
{1, 1, -1, -1},
|
|
{-1, 1, -1, -1},
|
|
{1, -1, -1, -1} };
|
|
unsigned sign_selector = get_bits(&gb, 6);
|
|
unsigned difference_selector = get_bits(&gb, 2);
|
|
y_base = 2 * get_bits(&gb, 5);
|
|
for (i = 0; i < 4; i++) {
|
|
y[i] = av_clip((int)y_base + offset_table[difference_selector] *
|
|
sign_table[sign_selector][i], 0, 63);
|
|
}
|
|
} else if (get_bits1(&gb)) {
|
|
if (get_bits1(&gb)) {
|
|
y_base = get_bits(&gb, 6);
|
|
} else {
|
|
unsigned adjust_index = get_bits(&gb, 3);
|
|
static const int8_t adjust[] = {-4, -3, -2, -1, 1, 2, 3, 4};
|
|
y_base = (y_base + adjust[adjust_index]) & 63;
|
|
}
|
|
for (i = 0; i < 4; i++)
|
|
y[i] = y_base;
|
|
}
|
|
|
|
if (get_bits1(&gb)) {
|
|
if (get_bits1(&gb)) {
|
|
cb = get_bits(&gb, 5);
|
|
cr = get_bits(&gb, 5);
|
|
} else {
|
|
unsigned adjust_index = get_bits(&gb, 3);
|
|
static const int8_t adjust[2][8] =
|
|
{ { 1, 1, 0, -1, -1, -1, 0, 1 },
|
|
{ 0, 1, 1, 1, 0, -1, -1, -1 } };
|
|
cb = (cb + adjust[0][adjust_index]) & 31;
|
|
cr = (cr + adjust[1][adjust_index]) & 31;
|
|
}
|
|
}
|
|
}
|
|
*yb++= y_base;
|
|
|
|
new_y[0] = y[0] * 4;
|
|
new_y[1] = y[1] * 4;
|
|
new_y[new_y_stride] = y[2] * 4;
|
|
new_y[new_y_stride + 1] = y[3] * 4;
|
|
*new_cb = cb * 8;
|
|
*new_cr = cr * 8;
|
|
|
|
if (old_y)
|
|
old_y += 2, old_cb++, old_cr++;
|
|
new_y += 2, new_cb++, new_cr++;
|
|
row_index++;
|
|
if (avctx->width / 2 == row_index) {
|
|
row_index = 0;
|
|
if (old_y) {
|
|
old_y += old_y_stride * 2 - avctx->width;
|
|
old_cb += old_cb_stride - avctx->width / 2;
|
|
old_cr += old_cr_stride - avctx->width / 2;
|
|
}
|
|
new_y += new_y_stride * 2 - avctx->width;
|
|
new_cb += new_cb_stride - avctx->width / 2;
|
|
new_cr += new_cr_stride - avctx->width / 2;
|
|
}
|
|
|
|
skip--;
|
|
}
|
|
|
|
av_log(avctx, AV_LOG_DEBUG,
|
|
"Escape sizes: %i, %i\n",
|
|
buf_size, get_bits_count(&gb) / 8);
|
|
|
|
if (s->frame.data[0])
|
|
avctx->release_buffer(avctx, &s->frame);
|
|
|
|
*(AVFrame*)data = s->frame = new_frame;
|
|
*data_size = sizeof(AVFrame);
|
|
|
|
return buf_size;
|
|
}
|
|
|
|
|
|
AVCodec ff_escape130_decoder = {
|
|
.name = "escape130",
|
|
.type = AVMEDIA_TYPE_VIDEO,
|
|
.id = CODEC_ID_ESCAPE130,
|
|
.priv_data_size = sizeof(Escape130Context),
|
|
.init = escape130_decode_init,
|
|
.close = escape130_decode_close,
|
|
.decode = escape130_decode_frame,
|
|
.capabilities = CODEC_CAP_DR1,
|
|
.long_name = NULL_IF_CONFIG_SMALL("Escape 130"),
|
|
};
|