ffmpeg/libavformat/yuv4mpeg.c

173 lines
4.5 KiB
C

/*
* YUV4MPEG format
* Copyright (c) 2001, 2002, 2003 Fabrice Bellard.
*
* This library 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 of the License, or (at your option) any later version.
*
* This library 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 this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include "avformat.h"
#define Y4M_MAGIC "YUV4MPEG2"
#define Y4M_FRAME_MAGIC "FRAME"
#define Y4M_LINE_MAX 256
static int yuv4_write_header(AVFormatContext *s)
{
AVStream *st;
int width, height;
int raten, rated, aspectn, aspectd, fps, fps1, n, gcd;
char buf[Y4M_LINE_MAX+1];
if (s->nb_streams != 1)
return -EIO;
st = s->streams[0];
width = st->codec.width;
height = st->codec.height;
#if 1
//this is identical to the code below for exact fps
av_reduce(&raten, &rated, st->codec.frame_rate, st->codec.frame_rate_base, (1UL<<31)-1);
#else
fps = st->codec.frame_rate;
fps1 = (((float)fps / st->codec.frame_rate_base) * 1000);
/* Sorry about this messy code, but mpeg2enc is very picky about
* the framerates it accepts. */
switch(fps1) {
case 23976:
raten = 24000; /* turn the framerate into a ratio */
rated = 1001;
break;
case 29970:
raten = 30000;
rated = 1001;
break;
case 25000:
raten = 25;
rated = 1;
break;
case 30000:
raten = 30;
rated = 1;
break;
case 24000:
raten = 24;
rated = 1;
break;
case 50000:
raten = 50;
rated = 1;
break;
case 59940:
raten = 60000;
rated = 1001;
break;
case 60000:
raten = 60;
rated = 1;
break;
default:
raten = st->codec.frame_rate; /* this setting should work, but often doesn't */
rated = st->codec.frame_rate_base;
gcd= av_gcd(raten, rated);
raten /= gcd;
rated /= gcd;
break;
}
#endif
aspectn = 1;
aspectd = 1; /* ffmpeg always uses a 1:1 aspect ratio */ //FIXME not true anymore
/* construct stream header, if this is the first frame */
n = snprintf(buf, sizeof(buf), "%s W%d H%d F%d:%d I%s A%d:%d\n",
Y4M_MAGIC,
width,
height,
raten, rated,
"p", /* ffmpeg seems to only output progressive video */
aspectn, aspectd);
if (n < 0) {
fprintf(stderr, "Error. YUV4MPEG stream header write failed.\n");
return -EIO;
} else {
put_buffer(&s->pb, buf, strlen(buf));
}
return 0;
}
static int yuv4_write_packet(AVFormatContext *s, int stream_index,
uint8_t *buf, int size, int force_pts)
{
AVStream *st = s->streams[stream_index];
ByteIOContext *pb = &s->pb;
AVPicture *picture;
int width, height;
int i, m;
char buf1[20];
uint8_t *ptr, *ptr1, *ptr2;
picture = (AVPicture *)buf;
/* construct frame header */
m = snprintf(buf1, sizeof(buf1), "%s \n", Y4M_FRAME_MAGIC);
put_buffer(pb, buf1, strlen(buf1));
width = st->codec.width;
height = st->codec.height;
ptr = picture->data[0];
for(i=0;i<height;i++) {
put_buffer(pb, ptr, width);
ptr += picture->linesize[0];
}
height >>= 1;
width >>= 1;
ptr1 = picture->data[1];
ptr2 = picture->data[2];
for(i=0;i<height;i++) { /* Cb */
put_buffer(pb, ptr1, width);
ptr1 += picture->linesize[1];
}
for(i=0;i<height;i++) { /* Cr */
put_buffer(pb, ptr2, width);
ptr2 += picture->linesize[2];
}
put_flush_packet(pb);
return 0;
}
static int yuv4_write_trailer(AVFormatContext *s)
{
return 0;
}
AVOutputFormat yuv4mpegpipe_oformat = {
"yuv4mpegpipe",
"YUV4MPEG pipe format",
"",
"yuv4mpeg",
0,
CODEC_ID_NONE,
CODEC_ID_RAWVIDEO,
yuv4_write_header,
yuv4_write_packet,
yuv4_write_trailer,
.flags = AVFMT_RAWPICTURE,
};