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FFmpeg/libavformat/img2enc.c
Anton Khirnov 9200514ad8 lavf: replace AVStream.codec with AVStream.codecpar
Currently, AVStream contains an embedded AVCodecContext instance, which
is used by demuxers to export stream parameters to the caller and by
muxers to receive stream parameters from the caller. It is also used
internally as the codec context that is passed to parsers.

In addition, it is also widely used by the callers as the decoding (when
demuxer) or encoding (when muxing) context, though this has been
officially discouraged since Libav 11.

There are multiple important problems with this approach:
    - the fields in AVCodecContext are in general one of
        * stream parameters
        * codec options
        * codec state
      However, it's not clear which ones are which. It is consequently
      unclear which fields are a demuxer allowed to set or a muxer allowed to
      read. This leads to erratic behaviour depending on whether decoding or
      encoding is being performed or not (and whether it uses the AVStream
      embedded codec context).
    - various synchronization issues arising from the fact that the same
      context is used by several different APIs (muxers/demuxers,
      parsers, bitstream filters and encoders/decoders) simultaneously, with
      there being no clear rules for who can modify what and the different
      processes being typically delayed with respect to each other.
    - avformat_find_stream_info() making it necessary to support opening
      and closing a single codec context multiple times, thus
      complicating the semantics of freeing various allocated objects in the
      codec context.

Those problems are resolved by replacing the AVStream embedded codec
context with a newly added AVCodecParameters instance, which stores only
the stream parameters exported by the demuxers or read by the muxers.
2016-02-23 17:01:58 +01:00

173 lines
6.0 KiB
C

/*
* Image format
* Copyright (c) 2000, 2001, 2002 Fabrice Bellard
* Copyright (c) 2004 Michael Niedermayer
*
* 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 "libavutil/intreadwrite.h"
#include "libavutil/avstring.h"
#include "libavutil/log.h"
#include "avformat.h"
#include "avio_internal.h"
#include "internal.h"
#include "libavutil/opt.h"
typedef struct VideoMuxData {
const AVClass *class; /**< Class for private options. */
int img_number;
int is_pipe;
char path[1024];
char tmp[1024];
int update;
} VideoMuxData;
static int write_header(AVFormatContext *s)
{
VideoMuxData *img = s->priv_data;
av_strlcpy(img->path, s->filename, sizeof(img->path));
snprintf(img->tmp, sizeof(img->tmp), "%s.tmp", s->filename);
/* find format */
if (s->oformat->flags & AVFMT_NOFILE)
img->is_pipe = 0;
else
img->is_pipe = 1;
return 0;
}
static int write_packet(AVFormatContext *s, AVPacket *pkt)
{
VideoMuxData *img = s->priv_data;
AVIOContext *pb[3];
char filename[1024];
AVCodecParameters *par = s->streams[pkt->stream_index]->codecpar;
int i;
if (!img->is_pipe) {
if (img->update) {
av_strlcpy(filename, img->path, sizeof(filename));
} else if (av_get_frame_filename(filename, sizeof(filename), img->path, img->img_number) < 0 &&
img->img_number > 1) {
av_log(s, AV_LOG_ERROR,
"Could not get frame filename number %d from pattern '%s'\n",
img->img_number, img->path);
return AVERROR(EIO);
}
for (i = 0; i < 3; i++) {
if (s->io_open(s, &pb[i], img->tmp, AVIO_FLAG_WRITE, NULL) < 0) {
av_log(s, AV_LOG_ERROR, "Could not open file : %s\n", img->tmp);
return AVERROR(EIO);
}
if (par->codec_id != AV_CODEC_ID_RAWVIDEO)
break;
filename[strlen(filename) - 1] = 'U' + i;
}
} else {
pb[0] = s->pb;
}
if (par->codec_id == AV_CODEC_ID_RAWVIDEO) {
int ysize = par->width * par->height;
avio_write(pb[0], pkt->data, ysize);
avio_write(pb[1], pkt->data + ysize, (pkt->size - ysize) / 2);
avio_write(pb[2], pkt->data + ysize + (pkt->size - ysize) / 2, (pkt->size - ysize) / 2);
ff_format_io_close(s, &pb[1]);
ff_format_io_close(s, &pb[2]);
} else {
if (ff_guess_image2_codec(s->filename) == AV_CODEC_ID_JPEG2000) {
AVStream *st = s->streams[0];
if (st->codecpar->extradata_size > 8 &&
AV_RL32(st->codecpar->extradata + 4) == MKTAG('j', 'p', '2', 'h')) {
if (pkt->size < 8 ||
AV_RL32(pkt->data + 4) != MKTAG('j', 'p', '2', 'c'))
goto error;
avio_wb32(pb[0], 12);
ffio_wfourcc(pb[0], "jP ");
avio_wb32(pb[0], 0x0D0A870A); // signature
avio_wb32(pb[0], 20);
ffio_wfourcc(pb[0], "ftyp");
ffio_wfourcc(pb[0], "jp2 ");
avio_wb32(pb[0], 0);
ffio_wfourcc(pb[0], "jp2 ");
avio_write(pb[0], st->codecpar->extradata, st->codecpar->extradata_size);
} else if (pkt->size < 8 ||
(!st->codecpar->extradata_size &&
AV_RL32(pkt->data + 4) != MKTAG('j', 'P', ' ', ' '))) { // signature
error:
av_log(s, AV_LOG_ERROR, "malformed JPEG 2000 codestream\n");
return -1;
}
}
avio_write(pb[0], pkt->data, pkt->size);
}
avio_flush(pb[0]);
if (!img->is_pipe) {
ff_format_io_close(s, &pb[0]);
ff_rename(img->tmp, filename);
}
img->img_number++;
return 0;
}
#define OFFSET(x) offsetof(VideoMuxData, x)
#define ENC AV_OPT_FLAG_ENCODING_PARAM
static const AVOption muxoptions[] = {
{ "start_number", "first number in the sequence", OFFSET(img_number), AV_OPT_TYPE_INT, { .i64 = 1 }, 1, INT_MAX, ENC },
{ "update", "continuously overwrite one file", OFFSET(update), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 1, ENC },
{ NULL },
};
#if CONFIG_IMAGE2_MUXER
static const AVClass img2mux_class = {
.class_name = "image2 muxer",
.item_name = av_default_item_name,
.option = muxoptions,
.version = LIBAVUTIL_VERSION_INT,
};
AVOutputFormat ff_image2_muxer = {
.name = "image2",
.long_name = NULL_IF_CONFIG_SMALL("image2 sequence"),
.extensions = "bmp,dpx,jpeg,jpg,ljpg,pam,pbm,pcx,pgm,pgmyuv,png,"
"ppm,sgi,tga,tif,tiff,jp2,xwd,sun,ras,rs,im1,im8,im24,"
"sunras,webp,xbm,j2c,pix",
.priv_data_size = sizeof(VideoMuxData),
.video_codec = AV_CODEC_ID_MJPEG,
.write_header = write_header,
.write_packet = write_packet,
.flags = AVFMT_NOTIMESTAMPS | AVFMT_NODIMENSIONS | AVFMT_NOFILE,
.priv_class = &img2mux_class,
};
#endif
#if CONFIG_IMAGE2PIPE_MUXER
AVOutputFormat ff_image2pipe_muxer = {
.name = "image2pipe",
.long_name = NULL_IF_CONFIG_SMALL("piped image2 sequence"),
.priv_data_size = sizeof(VideoMuxData),
.video_codec = AV_CODEC_ID_MJPEG,
.write_header = write_header,
.write_packet = write_packet,
.flags = AVFMT_NOTIMESTAMPS | AVFMT_NODIMENSIONS
};
#endif