FFmpeg/libavcodec/yuv4dec.c
2012-01-04 19:45:46 +01:00

110 lines
3.1 KiB
C

/*
* libquicktime yuv4 decoder
*
* Copyright (c) 2011 Carl Eugen Hoyos
*
* 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"
static av_cold int yuv4_decode_init(AVCodecContext *avctx)
{
avctx->pix_fmt = PIX_FMT_YUV420P;
avctx->coded_frame = avcodec_alloc_frame();
if (!avctx->coded_frame) {
av_log(avctx, AV_LOG_ERROR, "Could not allocate frame.\n");
return AVERROR(ENOMEM);
}
return 0;
}
static int yuv4_decode_frame(AVCodecContext *avctx, void *data,
int *data_size, AVPacket *avpkt)
{
AVFrame *pic = avctx->coded_frame;
const uint8_t *src = avpkt->data;
uint8_t *y, *u, *v;
int i, j;
if (pic->data[0])
avctx->release_buffer(avctx, pic);
if (avpkt->size < 6 * (avctx->width + 1 >> 1) * (avctx->height + 1 >> 1)) {
av_log(avctx, AV_LOG_ERROR, "Insufficient input data.\n");
return AVERROR(EINVAL);
}
pic->reference = 0;
if (avctx->get_buffer(avctx, pic) < 0) {
av_log(avctx, AV_LOG_ERROR, "Could not allocate buffer.\n");
return AVERROR(ENOMEM);
}
pic->key_frame = 1;
pic->pict_type = AV_PICTURE_TYPE_I;
y = pic->data[0];
u = pic->data[1];
v = pic->data[2];
for (i = 0; i < (avctx->height + 1) >> 1; i++) {
for (j = 0; j < (avctx->width + 1) >> 1; j++) {
u[j] = *src++ ^ 0x80;
v[j] = *src++ ^ 0x80;
y[ 2 * j ] = *src++;
y[ 2 * j + 1] = *src++;
y[pic->linesize[0] + 2 * j ] = *src++;
y[pic->linesize[0] + 2 * j + 1] = *src++;
}
y += 2 * pic->linesize[0];
u += pic->linesize[1];
v += pic->linesize[2];
}
*data_size = sizeof(AVFrame);
*(AVFrame *)data = *pic;
return avpkt->size;
}
static av_cold int yuv4_decode_close(AVCodecContext *avctx)
{
if (avctx->coded_frame->data[0])
avctx->release_buffer(avctx, avctx->coded_frame);
av_freep(&avctx->coded_frame);
return 0;
}
AVCodec ff_yuv4_decoder = {
.name = "yuv4",
.type = AVMEDIA_TYPE_VIDEO,
.id = CODEC_ID_YUV4,
.init = yuv4_decode_init,
.decode = yuv4_decode_frame,
.close = yuv4_decode_close,
.capabilities = CODEC_CAP_DR1,
.long_name = NULL_IF_CONFIG_SMALL("Uncompressed packed 4:2:0"),
};