1
0
mirror of https://github.com/FFmpeg/FFmpeg.git synced 2024-11-21 10:55:51 +02:00
FFmpeg/libavformat/img2dec.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

336 lines
10 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/avstring.h"
#include "libavutil/log.h"
#include "libavutil/opt.h"
#include "libavutil/pixdesc.h"
#include "libavutil/parseutils.h"
#include "avformat.h"
#include "internal.h"
typedef struct VideoDemuxData {
const AVClass *class; /**< Class for private options. */
int img_first;
int img_last;
int img_number;
int img_count;
int is_pipe;
char path[1024];
char *pixel_format; /**< Set by a private option. */
char *video_size; /**< Set by a private option. */
char *framerate; /**< Set by a private option. */
int loop;
int start_number;
} VideoDemuxData;
static const int sizes[][2] = {
{ 640, 480 },
{ 720, 480 },
{ 720, 576 },
{ 352, 288 },
{ 352, 240 },
{ 160, 128 },
{ 512, 384 },
{ 640, 352 },
{ 640, 240 },
};
static int infer_size(int *width_ptr, int *height_ptr, int size)
{
int i;
for (i = 0; i < FF_ARRAY_ELEMS(sizes); i++) {
if ((sizes[i][0] * sizes[i][1]) == size) {
*width_ptr = sizes[i][0];
*height_ptr = sizes[i][1];
return 0;
}
}
return -1;
}
/* return -1 if no image found */
static int find_image_range(int *pfirst_index, int *plast_index,
const char *path, int max_start)
{
char buf[1024];
int range, last_index, range1, first_index;
/* find the first image */
for (first_index = 0; first_index < max_start; first_index++) {
if (av_get_frame_filename(buf, sizeof(buf), path, first_index) < 0) {
*pfirst_index =
*plast_index = 1;
if (avio_check(buf, AVIO_FLAG_READ) > 0)
return 0;
return -1;
}
if (avio_check(buf, AVIO_FLAG_READ) > 0)
break;
}
if (first_index == 5)
goto fail;
/* find the last image */
last_index = first_index;
for (;;) {
range = 0;
for (;;) {
if (!range)
range1 = 1;
else
range1 = 2 * range;
if (av_get_frame_filename(buf, sizeof(buf), path,
last_index + range1) < 0)
goto fail;
if (avio_check(buf, AVIO_FLAG_READ) <= 0)
break;
range = range1;
/* just in case... */
if (range >= (1 << 30))
goto fail;
}
/* we are sure than image last_index + range exists */
if (!range)
break;
last_index += range;
}
*pfirst_index = first_index;
*plast_index = last_index;
return 0;
fail:
return -1;
}
static int img_read_probe(AVProbeData *p)
{
if (p->filename && ff_guess_image2_codec(p->filename)) {
if (av_filename_number_test(p->filename))
return AVPROBE_SCORE_MAX;
else
return AVPROBE_SCORE_EXTENSION;
}
return 0;
}
static int img_read_header(AVFormatContext *s1)
{
VideoDemuxData *s = s1->priv_data;
int first_index, last_index, ret = 0;
int width = 0, height = 0;
AVStream *st;
enum AVPixelFormat pix_fmt = AV_PIX_FMT_NONE;
AVRational framerate;
s1->ctx_flags |= AVFMTCTX_NOHEADER;
st = avformat_new_stream(s1, NULL);
if (!st) {
return AVERROR(ENOMEM);
}
if (s->pixel_format &&
(pix_fmt = av_get_pix_fmt(s->pixel_format)) == AV_PIX_FMT_NONE) {
av_log(s1, AV_LOG_ERROR, "No such pixel format: %s.\n",
s->pixel_format);
return AVERROR(EINVAL);
}
if (s->video_size &&
(ret = av_parse_video_size(&width, &height, s->video_size)) < 0) {
av_log(s, AV_LOG_ERROR,
"Could not parse video size: %s.\n", s->video_size);
return ret;
}
if ((ret = av_parse_video_rate(&framerate, s->framerate)) < 0) {
av_log(s, AV_LOG_ERROR,
"Could not parse framerate: %s.\n", s->framerate);
return ret;
}
av_strlcpy(s->path, s1->filename, sizeof(s->path));
s->img_number = 0;
s->img_count = 0;
/* find format */
if (s1->iformat->flags & AVFMT_NOFILE)
s->is_pipe = 0;
else {
s->is_pipe = 1;
st->need_parsing = AVSTREAM_PARSE_FULL;
}
avpriv_set_pts_info(st, 60, framerate.den, framerate.num);
if (width && height) {
st->codecpar->width = width;
st->codecpar->height = height;
}
if (!s->is_pipe) {
if (find_image_range(&first_index, &last_index, s->path,
FFMAX(s->start_number, 5)) < 0)
return AVERROR(ENOENT);
s->img_first = first_index;
s->img_last = last_index;
s->img_number = s->start_number != 1 ? s->start_number : first_index;
/* compute duration */
st->start_time = 0;
st->duration = last_index - first_index + 1;
}
if (s1->video_codec_id) {
st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
st->codecpar->codec_id = s1->video_codec_id;
} else if (s1->audio_codec_id) {
st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
st->codecpar->codec_id = s1->audio_codec_id;
} else {
st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
st->codecpar->codec_id = ff_guess_image2_codec(s->path);
}
if (st->codecpar->codec_type == AVMEDIA_TYPE_VIDEO &&
pix_fmt != AV_PIX_FMT_NONE)
st->codecpar->format = pix_fmt;
return 0;
}
static int img_read_packet(AVFormatContext *s1, AVPacket *pkt)
{
VideoDemuxData *s = s1->priv_data;
char filename[1024];
int i, res;
int size[3] = { 0 }, ret[3] = { 0 };
AVIOContext *f[3] = { NULL };
AVCodecParameters *par = s1->streams[0]->codecpar;
if (!s->is_pipe) {
/* loop over input */
if (s->loop && s->img_number > s->img_last) {
s->img_number = s->img_first;
}
if (s->img_number > s->img_last)
return AVERROR_EOF;
if (av_get_frame_filename(filename, sizeof(filename),
s->path,
s->img_number) < 0 && s->img_number > 1)
return AVERROR(EIO);
for (i = 0; i < 3; i++) {
if (s1->io_open(s1, &f[i], filename, AVIO_FLAG_READ, NULL) < 0) {
if (i >= 1)
break;
av_log(s1, AV_LOG_ERROR, "Could not open file : %s\n",
filename);
return AVERROR(EIO);
}
size[i] = avio_size(f[i]);
if (par->codec_id != AV_CODEC_ID_RAWVIDEO)
break;
filename[strlen(filename) - 1] = 'U' + i;
}
if (par->codec_id == AV_CODEC_ID_RAWVIDEO && !par->width)
infer_size(&par->width, &par->height, size[0]);
} else {
f[0] = s1->pb;
if (f[0]->eof_reached)
return AVERROR(EIO);
size[0] = 4096;
}
res = av_new_packet(pkt, size[0] + size[1] + size[2]);
if (res < 0)
return res;
pkt->stream_index = 0;
pkt->flags |= AV_PKT_FLAG_KEY;
pkt->size = 0;
for (i = 0; i < 3; i++) {
if (f[i]) {
ret[i] = avio_read(f[i], pkt->data + pkt->size, size[i]);
if (!s->is_pipe)
ff_format_io_close(s1, &f[i]);
if (ret[i] > 0)
pkt->size += ret[i];
}
}
if (ret[0] <= 0 || ret[1] < 0 || ret[2] < 0) {
av_packet_unref(pkt);
return AVERROR(EIO); /* signal EOF */
} else {
s->img_count++;
s->img_number++;
return 0;
}
}
#define OFFSET(x) offsetof(VideoDemuxData, x)
#define DEC AV_OPT_FLAG_DECODING_PARAM
static const AVOption options[] = {
{ "pixel_format", "", OFFSET(pixel_format), AV_OPT_TYPE_STRING, { .str = NULL }, 0, 0, DEC },
{ "video_size", "", OFFSET(video_size), AV_OPT_TYPE_STRING, { .str = NULL }, 0, 0, DEC },
{ "framerate", "", OFFSET(framerate), AV_OPT_TYPE_STRING, { .str = "25" }, 0, 0, DEC },
{ "loop", "", OFFSET(loop), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 1, DEC },
{ "start_number", "first number in the sequence", OFFSET(start_number), AV_OPT_TYPE_INT, { .i64 = 1 }, 1, INT_MAX, DEC },
{ NULL },
};
#if CONFIG_IMAGE2_DEMUXER
static const AVClass img2_class = {
.class_name = "image2 demuxer",
.item_name = av_default_item_name,
.option = options,
.version = LIBAVUTIL_VERSION_INT,
};
AVInputFormat ff_image2_demuxer = {
.name = "image2",
.long_name = NULL_IF_CONFIG_SMALL("image2 sequence"),
.priv_data_size = sizeof(VideoDemuxData),
.read_probe = img_read_probe,
.read_header = img_read_header,
.read_packet = img_read_packet,
.flags = AVFMT_NOFILE,
.priv_class = &img2_class,
};
#endif
#if CONFIG_IMAGE2PIPE_DEMUXER
static const AVClass img2pipe_class = {
.class_name = "image2pipe demuxer",
.item_name = av_default_item_name,
.option = options,
.version = LIBAVUTIL_VERSION_INT,
};
AVInputFormat ff_image2pipe_demuxer = {
.name = "image2pipe",
.long_name = NULL_IF_CONFIG_SMALL("piped image2 sequence"),
.priv_data_size = sizeof(VideoDemuxData),
.read_header = img_read_header,
.read_packet = img_read_packet,
.priv_class = &img2pipe_class,
};
#endif