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FFmpeg/libavcodec/avrndec.c
Anton Khirnov 9e4225cf7f Handle AVID MJPEG streams directly in the MJPEG decoder.
AVID streams - currently handled by the AVRN decoder - can be (depending
on extradata contents) either MJPEG or raw video. To decode the MJPEG
variant, the AVRN decoder currently instantiates a MJPEG decoder
internally and forwards decoded frames to the caller (possibly after
cropping them).

This is suboptimal, because the AVRN decoder does not forward all the
features of the internal MJPEG decoder, such as direct rendering.
Handling such forwarding in a full and generic manner would be quite
hard, so it is simpler to just handle those streams in the MJPEG decoder
directly.

The AVRN decoder, which now handles only the raw streams, can now be
marked as supporting direct rendering.

This also removes the last remaining internal use of the obsolete
decoding API.
2021-02-25 11:46:28 +01:00

104 lines
3.2 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 "internal.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, void *data,
int *got_frame, AVPacket *avpkt)
{
AVRnContext *a = avctx->priv_data;
AVFrame *p = 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;
p->pict_type= AV_PICTURE_TYPE_I;
p->key_frame= 1;
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;
}
AVCodec ff_avrn_decoder = {
.name = "avrn",
.long_name = NULL_IF_CONFIG_SMALL("Avid AVI Codec"),
.type = AVMEDIA_TYPE_VIDEO,
.id = AV_CODEC_ID_AVRN,
.priv_data_size = sizeof(AVRnContext),
.init = init,
.decode = decode_frame,
.max_lowres = 3,
.capabilities = AV_CODEC_CAP_DR1,
.caps_internal = FF_CODEC_CAP_INIT_THREADSAFE | FF_CODEC_CAP_INIT_CLEANUP,
};