mirror of https://git.ffmpeg.org/ffmpeg.git
109 lines
3.3 KiB
C
109 lines
3.3 KiB
C
/*
|
|
* Aura 2 decoder
|
|
*
|
|
* 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
|
|
* Aura 2 decoder
|
|
*/
|
|
|
|
#include "avcodec.h"
|
|
#include "codec_internal.h"
|
|
#include "internal.h"
|
|
#include "libavutil/internal.h"
|
|
|
|
static av_cold int aura_decode_init(AVCodecContext *avctx)
|
|
{
|
|
/* width needs to be divisible by 4 for this codec to work */
|
|
if (avctx->width & 0x3)
|
|
return AVERROR(EINVAL);
|
|
avctx->pix_fmt = AV_PIX_FMT_YUV422P;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int aura_decode_frame(AVCodecContext *avctx, AVFrame *frame,
|
|
int *got_frame, AVPacket *pkt)
|
|
{
|
|
uint8_t *Y, *U, *V;
|
|
uint8_t val;
|
|
int x, y, ret;
|
|
const uint8_t *buf = pkt->data;
|
|
|
|
/* prediction error tables (make it clear that they are signed values) */
|
|
const int8_t *delta_table = (const int8_t*)buf + 16;
|
|
|
|
if (pkt->size != 48 + avctx->height * avctx->width) {
|
|
av_log(avctx, AV_LOG_ERROR, "got a buffer with %d bytes when %d were expected\n",
|
|
pkt->size, 48 + avctx->height * avctx->width);
|
|
return AVERROR_INVALIDDATA;
|
|
}
|
|
|
|
/* pixel data starts 48 bytes in, after 3x16-byte tables */
|
|
buf += 48;
|
|
|
|
if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
|
|
return ret;
|
|
|
|
Y = frame->data[0];
|
|
U = frame->data[1];
|
|
V = frame->data[2];
|
|
|
|
/* iterate through each line in the height */
|
|
for (y = 0; y < avctx->height; y++) {
|
|
/* reset predictors */
|
|
val = *buf++;
|
|
U[0] = val & 0xF0;
|
|
Y[0] = val << 4;
|
|
val = *buf++;
|
|
V[0] = val & 0xF0;
|
|
Y[1] = Y[0] + delta_table[val & 0xF];
|
|
Y += 2; U++; V++;
|
|
|
|
/* iterate through the remaining pixel groups (4 pixels/group) */
|
|
for (x = 1; x < (avctx->width >> 1); x++) {
|
|
val = *buf++;
|
|
U[0] = U[-1] + delta_table[val >> 4];
|
|
Y[0] = Y[-1] + delta_table[val & 0xF];
|
|
val = *buf++;
|
|
V[0] = V[-1] + delta_table[val >> 4];
|
|
Y[1] = Y[ 0] + delta_table[val & 0xF];
|
|
Y += 2; U++; V++;
|
|
}
|
|
Y += frame->linesize[0] - avctx->width;
|
|
U += frame->linesize[1] - (avctx->width >> 1);
|
|
V += frame->linesize[2] - (avctx->width >> 1);
|
|
}
|
|
|
|
*got_frame = 1;
|
|
|
|
return pkt->size;
|
|
}
|
|
|
|
const FFCodec ff_aura2_decoder = {
|
|
.p.name = "aura2",
|
|
.p.long_name = NULL_IF_CONFIG_SMALL("Auravision Aura 2"),
|
|
.p.type = AVMEDIA_TYPE_VIDEO,
|
|
.p.id = AV_CODEC_ID_AURA2,
|
|
.init = aura_decode_init,
|
|
FF_CODEC_DECODE_CB(aura_decode_frame),
|
|
.p.capabilities = AV_CODEC_CAP_DR1,
|
|
.caps_internal = FF_CODEC_CAP_INIT_THREADSAFE,
|
|
};
|