ffmpeg/libavcodec/frwu.c

124 lines
3.7 KiB
C

/*
* Forward Uncompressed
*
* Copyright (c) 2009 Reimar Döffinger <Reimar.Doeffinger@gmx.de>
*
* 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
*/
#include "avcodec.h"
#include "bytestream.h"
#include "libavutil/intreadwrite.h"
static av_cold int decode_init(AVCodecContext *avctx)
{
if (avctx->width & 1) {
av_log(avctx, AV_LOG_ERROR, "FRWU needs even width\n");
return -1;
}
avctx->pix_fmt = PIX_FMT_UYVY422;
avctx->coded_frame = avcodec_alloc_frame();
if (!avctx->coded_frame)
return AVERROR(ENOMEM);
return 0;
}
static int decode_frame(AVCodecContext *avctx, void *data, int *data_size,
AVPacket *avpkt)
{
int field;
AVFrame *pic = avctx->coded_frame;
const uint8_t *buf = avpkt->data;
const uint8_t *buf_end = buf + avpkt->size;
if (pic->data[0])
avctx->release_buffer(avctx, pic);
if (avpkt->size < avctx->width * 2 * avctx->height + 4 + 2*8) {
av_log(avctx, AV_LOG_ERROR, "Packet is too small.\n");
return -1;
}
if (bytestream_get_le32(&buf) != AV_RL32("FRW1")) {
av_log(avctx, AV_LOG_ERROR, "incorrect marker\n");
return -1;
}
pic->reference = 0;
if (avctx->get_buffer(avctx, pic) < 0)
return -1;
pic->pict_type = AV_PICTURE_TYPE_I;
pic->key_frame = 1;
pic->interlaced_frame = 1;
pic->top_field_first = 1;
for (field = 0; field < 2; field++) {
int i;
int field_h = (avctx->height + !field) >> 1;
int field_size, min_field_size = avctx->width * 2 * field_h;
uint8_t *dst = pic->data[0];
if (buf_end - buf < 8)
return -1;
buf += 4; // flags? 0x80 == bottom field maybe?
field_size = bytestream_get_le32(&buf);
if (field_size < min_field_size) {
av_log(avctx, AV_LOG_ERROR, "Field size %i is too small (required %i)\n", field_size, min_field_size);
return -1;
}
if (buf_end - buf < field_size) {
av_log(avctx, AV_LOG_ERROR, "Packet is too small, need %i, have %i\n", field_size, (int)(buf_end - buf));
return -1;
}
if (field)
dst += pic->linesize[0];
for (i = 0; i < field_h; i++) {
memcpy(dst, buf, avctx->width * 2);
buf += avctx->width * 2;
dst += pic->linesize[0] << 1;
}
buf += field_size - min_field_size;
}
*data_size = sizeof(AVFrame);
*(AVFrame*)data = *pic;
return avpkt->size;
}
static av_cold int decode_close(AVCodecContext *avctx)
{
AVFrame *pic = avctx->coded_frame;
if (pic->data[0])
avctx->release_buffer(avctx, pic);
av_freep(&avctx->coded_frame);
return 0;
}
AVCodec ff_frwu_decoder = {
.name = "FRWU",
.type = AVMEDIA_TYPE_VIDEO,
.id = CODEC_ID_FRWU,
.init = decode_init,
.close = decode_close,
.decode = decode_frame,
.capabilities = CODEC_CAP_DR1,
.long_name = NULL_IF_CONFIG_SMALL("Forward Uncompressed"),
};