ffmpeg/libavcodec/avrndec.c

101 lines
3.1 KiB
C

/*
* AVRn decoder
* Copyright (c) 2012 Michael Niedermayer
*
* 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"
#include "codec_internal.h"
#include "decode.h"
#include "libavutil/imgutils.h"
typedef struct {
int interlace;
int tff;
} AVRnContext;
static av_cold int init(AVCodecContext *avctx)
{
AVRnContext *a = avctx->priv_data;
int ret;
if ((ret = av_image_check_size(avctx->width, avctx->height, 0, avctx)) < 0)
return ret;
avctx->pix_fmt = AV_PIX_FMT_UYVY422;
if(avctx->extradata_size >= 9 && avctx->extradata[4]+28 < avctx->extradata_size) {
int ndx = avctx->extradata[4] + 4;
a->interlace = !memcmp(avctx->extradata + ndx, "1:1(", 4);
if(a->interlace) {
a->tff = avctx->extradata[ndx + 24] == 1;
}
}
return 0;
}
static int decode_frame(AVCodecContext *avctx, AVFrame *p,
int *got_frame, AVPacket *avpkt)
{
AVRnContext *a = avctx->priv_data;
const uint8_t *buf = avpkt->data;
int buf_size = avpkt->size;
int y, ret, true_height;
true_height = buf_size / (2*avctx->width);
if(buf_size < 2*avctx->width * avctx->height) {
av_log(avctx, AV_LOG_ERROR, "packet too small\n");
return AVERROR_INVALIDDATA;
}
if ((ret = ff_get_buffer(avctx, p, 0)) < 0)
return ret;
if(a->interlace) {
buf += (true_height - avctx->height)*avctx->width;
for(y = 0; y < avctx->height-1; y+=2) {
memcpy(p->data[0] + (y+ a->tff)*p->linesize[0], buf , 2*avctx->width);
memcpy(p->data[0] + (y+!a->tff)*p->linesize[0], buf + avctx->width*true_height+4, 2*avctx->width);
buf += 2*avctx->width;
}
} else {
buf += (true_height - avctx->height)*avctx->width*2;
for(y = 0; y < avctx->height; y++) {
memcpy(p->data[0] + y*p->linesize[0], buf, 2*avctx->width);
buf += 2*avctx->width;
}
}
*got_frame = 1;
return buf_size;
}
const FFCodec ff_avrn_decoder = {
.p.name = "avrn",
CODEC_LONG_NAME("Avid AVI Codec"),
.p.type = AVMEDIA_TYPE_VIDEO,
.p.id = AV_CODEC_ID_AVRN,
.priv_data_size = sizeof(AVRnContext),
.init = init,
FF_CODEC_DECODE_CB(decode_frame),
.p.capabilities = AV_CODEC_CAP_DR1,
.caps_internal = FF_CODEC_CAP_INIT_CLEANUP,
};