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FFmpeg/libavcodec/eatgq.c
Anton Khirnov 7ea1b3472a lavc: deprecate the use of AVCodecContext.time_base for decoding 
When decoding, this field holds the inverse of the framerate that can be
written in the headers for some codecs. Using a field called 'time_base'
for this is very misleading, as there are no timestamps associated with
it. Furthermore, this field is used for a very different purpose during
encoding.

Add a new field, called 'framerate', to replace the use of time_base for
decoding.
2014-10-15 06:37:43 +00:00

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/*
* Electronic Arts TGQ Video Decoder
* Copyright (c) 2007-2008 Peter Ross <pross@xvid.org>
*
* 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 St, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* Electronic Arts TGQ Video Decoder
* @author Peter Ross <pross@xvid.org>
*
* Technical details here:
* http://wiki.multimedia.cx/index.php?title=Electronic_Arts_TGQ
*/
#include "avcodec.h"
#define BITSTREAM_READER_LE
#include "get_bits.h"
#include "bytestream.h"
#include "idctdsp.h"
#include "aandcttab.h"
#include "eaidct.h"
#include "internal.h"
typedef struct TgqContext {
AVCodecContext *avctx;
int width, height;
ScanTable scantable;
int qtable[64];
DECLARE_ALIGNED(16, int16_t, block)[6][64];
GetByteContext gb;
} TgqContext;
static av_cold int tgq_decode_init(AVCodecContext *avctx)
{
TgqContext *s = avctx->priv_data;
uint8_t idct_permutation[64];
s->avctx = avctx;
ff_init_scantable_permutation(idct_permutation, FF_IDCT_PERM_NONE);
ff_init_scantable(idct_permutation, &s->scantable, ff_zigzag_direct);
avctx->framerate = (AVRational){ 15, 1 };
avctx->pix_fmt = AV_PIX_FMT_YUV420P;
return 0;
}
static void tgq_decode_block(TgqContext *s, int16_t block[64], GetBitContext *gb)
{
uint8_t *perm = s->scantable.permutated;
int i, j, value;
block[0] = get_sbits(gb, 8) * s->qtable[0];
for (i = 1; i < 64;) {
switch (show_bits(gb, 3)) {
case 4:
block[perm[i++]] = 0;
case 0:
block[perm[i++]] = 0;
skip_bits(gb, 3);
break;
case 5:
case 1:
skip_bits(gb, 2);
value = get_bits(gb, 6);
for (j = 0; j < value; j++)
block[perm[i++]] = 0;
break;
case 6:
skip_bits(gb, 3);
block[perm[i]] = -s->qtable[perm[i]];
i++;
break;
case 2:
skip_bits(gb, 3);
block[perm[i]] = s->qtable[perm[i]];
i++;
break;
case 7: // 111b
case 3: // 011b
skip_bits(gb, 2);
if (show_bits(gb, 6) == 0x3F) {
skip_bits(gb, 6);
block[perm[i]] = get_sbits(gb, 8) * s->qtable[perm[i]];
} else {
block[perm[i]] = get_sbits(gb, 6) * s->qtable[perm[i]];
}
i++;
break;
}
}
block[0] += 128 << 4;
}
static void tgq_idct_put_mb(TgqContext *s, int16_t (*block)[64], AVFrame *frame,
int mb_x, int mb_y)
{
int linesize = frame->linesize[0];
uint8_t *dest_y = frame->data[0] + (mb_y * 16 * linesize) + mb_x * 16;
uint8_t *dest_cb = frame->data[1] + (mb_y * 8 * frame->linesize[1]) + mb_x * 8;
uint8_t *dest_cr = frame->data[2] + (mb_y * 8 * frame->linesize[2]) + mb_x * 8;
ff_ea_idct_put_c(dest_y , linesize, block[0]);
ff_ea_idct_put_c(dest_y + 8, linesize, block[1]);
ff_ea_idct_put_c(dest_y + 8 * linesize , linesize, block[2]);
ff_ea_idct_put_c(dest_y + 8 * linesize + 8, linesize, block[3]);
if (!(s->avctx->flags & CODEC_FLAG_GRAY)) {
ff_ea_idct_put_c(dest_cb, frame->linesize[1], block[4]);
ff_ea_idct_put_c(dest_cr, frame->linesize[2], block[5]);
}
}
static inline void tgq_dconly(TgqContext *s, unsigned char *dst,
int dst_stride, int dc)
{
int level = av_clip_uint8((dc*s->qtable[0] + 2056) >> 4);
int j;
for (j = 0; j < 8; j++)
memset(dst + j * dst_stride, level, 8);
}
static void tgq_idct_put_mb_dconly(TgqContext *s, AVFrame *frame,
int mb_x, int mb_y, const int8_t *dc)
{
int linesize = frame->linesize[0];
uint8_t *dest_y = frame->data[0] + (mb_y * 16 * linesize) + mb_x * 16;
uint8_t *dest_cb = frame->data[1] + (mb_y * 8 * frame->linesize[1]) + mb_x * 8;
uint8_t *dest_cr = frame->data[2] + (mb_y * 8 * frame->linesize[2]) + mb_x * 8;
tgq_dconly(s, dest_y, linesize, dc[0]);
tgq_dconly(s, dest_y + 8, linesize, dc[1]);
tgq_dconly(s, dest_y + 8 * linesize, linesize, dc[2]);
tgq_dconly(s, dest_y + 8 * linesize + 8, linesize, dc[3]);
if (!(s->avctx->flags & CODEC_FLAG_GRAY)) {
tgq_dconly(s, dest_cb, frame->linesize[1], dc[4]);
tgq_dconly(s, dest_cr, frame->linesize[2], dc[5]);
}
}
static void tgq_decode_mb(TgqContext *s, AVFrame *frame, int mb_y, int mb_x)
{
int mode;
int i;
int8_t dc[6];
mode = bytestream2_get_byte(&s->gb);
if (mode > 12) {
GetBitContext gb;
init_get_bits(&gb, s->gb.buffer, FFMIN(s->gb.buffer_end - s->gb.buffer, mode) * 8);
for (i = 0; i < 6; i++)
tgq_decode_block(s, s->block[i], &gb);
tgq_idct_put_mb(s, s->block, frame, mb_x, mb_y);
bytestream2_skip(&s->gb, mode);
} else {
if (mode == 3) {
memset(dc, bytestream2_get_byte(&s->gb), 4);
dc[4] = bytestream2_get_byte(&s->gb);
dc[5] = bytestream2_get_byte(&s->gb);
} else if (mode == 6) {
bytestream2_get_buffer(&s->gb, dc, 6);
} else if (mode == 12) {
for (i = 0; i < 6; i++) {
dc[i] = bytestream2_get_byte(&s->gb);
bytestream2_skip(&s->gb, 1);
}
} else {
av_log(s->avctx, AV_LOG_ERROR, "unsupported mb mode %i\n", mode);
}
tgq_idct_put_mb_dconly(s, frame, mb_x, mb_y, dc);
}
}
static void tgq_calculate_qtable(TgqContext *s, int quant)
{
int i, j;
const int a = (14 * (100 - quant)) / 100 + 1;
const int b = (11 * (100 - quant)) / 100 + 4;
for (j = 0; j < 8; j++)
for (i = 0; i < 8; i++)
s->qtable[j * 8 + i] = ((a * (j + i) / (7 + 7) + b) *
ff_inv_aanscales[j * 8 + i]) >> (14 - 4);
}
static int tgq_decode_frame(AVCodecContext *avctx,
void *data, int *got_frame,
AVPacket *avpkt)
{
const uint8_t *buf = avpkt->data;
int buf_size = avpkt->size;
TgqContext *s = avctx->priv_data;
AVFrame *frame = data;
int x, y, ret;
int big_endian = AV_RL32(&buf[4]) > 0x000FFFFF;
if (buf_size < 16) {
av_log(avctx, AV_LOG_WARNING, "truncated header\n");
return AVERROR_INVALIDDATA;
}
bytestream2_init(&s->gb, buf + 8, buf_size - 8);
if (big_endian) {
s->width = bytestream2_get_be16u(&s->gb);
s->height = bytestream2_get_be16u(&s->gb);
} else {
s->width = bytestream2_get_le16u(&s->gb);
s->height = bytestream2_get_le16u(&s->gb);
}
ret = ff_set_dimensions(s->avctx, s->width, s->height);
if (ret < 0)
return ret;
tgq_calculate_qtable(s, bytestream2_get_byteu(&s->gb));
bytestream2_skip(&s->gb, 3);
if ((ret = ff_get_buffer(avctx, frame, 0)) < 0) {
av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
return ret;
}
frame->key_frame = 1;
frame->pict_type = AV_PICTURE_TYPE_I;
for (y = 0; y < FFALIGN(avctx->height, 16) >> 4; y++)
for (x = 0; x < FFALIGN(avctx->width, 16) >> 4; x++)
tgq_decode_mb(s, frame, y, x);
*got_frame = 1;
return avpkt->size;
}
AVCodec ff_eatgq_decoder = {
.name = "eatgq",
.long_name = NULL_IF_CONFIG_SMALL("Electronic Arts TGQ video"),
.type = AVMEDIA_TYPE_VIDEO,
.id = AV_CODEC_ID_TGQ,
.priv_data_size = sizeof(TgqContext),
.init = tgq_decode_init,
.decode = tgq_decode_frame,
.capabilities = CODEC_CAP_DR1,
};
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