FFmpeg/libavcodec/xl.c
2012-03-01 23:11:10 +01:00

158 lines
4.2 KiB
C

/*
* Miro VideoXL codec
* Copyright (c) 2004 Konstantin Shishkov
*
* 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
* Miro VideoXL codec.
*/
#include "libavutil/intreadwrite.h"
#include "avcodec.h"
typedef struct VideoXLContext{
AVCodecContext *avctx;
AVFrame pic;
} VideoXLContext;
static const int xl_table[32] = {
0, 1, 2, 3, 4, 5, 6, 7,
8, 9, 12, 15, 20, 25, 34, 46,
64, 82, 94, 103, 108, 113, 116, 119,
120, 121, 122, 123, 124, 125, 126, 127};
static int decode_frame(AVCodecContext *avctx,
void *data, int *data_size,
AVPacket *avpkt)
{
const uint8_t *buf = avpkt->data;
int buf_size = avpkt->size;
VideoXLContext * const a = avctx->priv_data;
AVFrame * const p = &a->pic;
uint8_t *Y, *U, *V;
int i, j;
int stride;
uint32_t val;
int y0, y1, y2, y3 = 0, c0 = 0, c1 = 0;
if(p->data[0])
avctx->release_buffer(avctx, p);
p->reference = 0;
if(avctx->get_buffer(avctx, p) < 0){
av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
return -1;
}
p->pict_type= AV_PICTURE_TYPE_I;
p->key_frame= 1;
Y = a->pic.data[0];
U = a->pic.data[1];
V = a->pic.data[2];
stride = avctx->width - 4;
if (buf_size < avctx->width * avctx->height) {
av_log(avctx, AV_LOG_ERROR, "Packet is too small\n");
return AVERROR_INVALIDDATA;
}
for (i = 0; i < avctx->height; i++) {
/* lines are stored in reversed order */
buf += stride;
for (j = 0; j < avctx->width; j += 4) {
/* value is stored in LE dword with word swapped */
val = AV_RL32(buf);
buf -= 4;
val = ((val >> 16) & 0xFFFF) | ((val & 0xFFFF) << 16);
if(!j)
y0 = (val & 0x1F) << 2;
else
y0 = y3 + xl_table[val & 0x1F];
val >>= 5;
y1 = y0 + xl_table[val & 0x1F];
val >>= 5;
y2 = y1 + xl_table[val & 0x1F];
val >>= 6; /* align to word */
y3 = y2 + xl_table[val & 0x1F];
val >>= 5;
if(!j)
c0 = (val & 0x1F) << 2;
else
c0 += xl_table[val & 0x1F];
val >>= 5;
if(!j)
c1 = (val & 0x1F) << 2;
else
c1 += xl_table[val & 0x1F];
Y[j + 0] = y0 << 1;
Y[j + 1] = y1 << 1;
Y[j + 2] = y2 << 1;
Y[j + 3] = y3 << 1;
U[j >> 2] = c0 << 1;
V[j >> 2] = c1 << 1;
}
buf += avctx->width + 4;
Y += a->pic.linesize[0];
U += a->pic.linesize[1];
V += a->pic.linesize[2];
}
*data_size = sizeof(AVFrame);
*(AVFrame*)data = a->pic;
return buf_size;
}
static av_cold int decode_init(AVCodecContext *avctx){
// VideoXLContext * const a = avctx->priv_data;
avctx->pix_fmt= PIX_FMT_YUV411P;
return 0;
}
static av_cold int decode_end(AVCodecContext *avctx){
VideoXLContext * const a = avctx->priv_data;
AVFrame *pic = &a->pic;
if (pic->data[0])
avctx->release_buffer(avctx, pic);
return 0;
}
AVCodec ff_xl_decoder = {
.name = "xl",
.type = AVMEDIA_TYPE_VIDEO,
.id = CODEC_ID_VIXL,
.priv_data_size = sizeof(VideoXLContext),
.init = decode_init,
.close = decode_end,
.decode = decode_frame,
.capabilities = CODEC_CAP_DR1,
.long_name = NULL_IF_CONFIG_SMALL("Miro VideoXL"),
};