chromium/third_party/ffmpeg/libavformat/rawdec.c

/*
 * RAW demuxers
 * Copyright (c) 2001 Fabrice Bellard
 * Copyright (c) 2005 Alex Beregszaszi
 *
 * 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 "config_components.h"

#include "avformat.h"
#include "demux.h"
#include "internal.h"
#include "rawdec.h"
#include "libavutil/opt.h"

#define RAW_PACKET_SIZE …

int ff_raw_read_partial_packet(AVFormatContext *s, AVPacket *pkt)
{ … }

int ff_raw_audio_read_header(AVFormatContext *s)
{ … }

/* MPEG-1/H.263 input */
int ff_raw_video_read_header(AVFormatContext *s)
{ … }

int ff_raw_subtitle_read_header(AVFormatContext *s)
{ … }

static int raw_data_read_header(AVFormatContext *s)
{ … }

/* Note: Do not forget to add new entries to the Makefile as well. */

#define OFFSET(x) …
#define DEC …
static const AVOption rawvideo_options[] = …;
#undef OFFSET

const AVClass ff_rawvideo_demuxer_class = …;

#define OFFSET(x) …
static const AVOption raw_options[] = …;

const AVClass ff_raw_demuxer_class = …;

#if CONFIG_DATA_DEMUXER
const FFInputFormat ff_data_demuxer = {
    .p.name         = "data",
    .p.long_name    = NULL_IF_CONFIG_SMALL("raw data"),
    .p.flags        = AVFMT_NOTIMESTAMPS,
    .p.priv_class   = &ff_raw_demuxer_class,
    .read_header    = raw_data_read_header,
    .read_packet    = ff_raw_read_partial_packet,
    .raw_codec_id   = AV_CODEC_ID_NONE,
    .priv_data_size = sizeof(FFRawDemuxerContext),\
};
#endif

#if CONFIG_MJPEG_DEMUXER
static int mjpeg_probe(const AVProbeData *p)
{
    int i;
    int state = -1;
    int nb_invalid = 0;
    int nb_frames = 0;

    for (i = 0; i < p->buf_size - 1; i++) {
        int c;
        if (p->buf[i] != 0xFF)
            continue;
        c = p->buf[i+1];
        switch (c) {
        case 0xD8:
            state = 0xD8;
            break;
        case 0xC0:
        case 0xC1:
        case 0xC2:
        case 0xC3:
        case 0xC5:
        case 0xC6:
        case 0xC7:
        case 0xF7:
            if (state == 0xD8) {
                state = 0xC0;
            } else
                nb_invalid++;
            break;
        case 0xDA:
            if (state == 0xC0) {
                state = 0xDA;
            } else
                nb_invalid++;
            break;
        case 0xD9:
            if (state == 0xDA) {
                state = 0xD9;
                nb_frames++;
            } else
                nb_invalid++;
            break;
        default:
            if (  (c >= 0x02 && c <= 0xBF)
                || c == 0xC8) {
                nb_invalid++;
            }
        }
    }

    if (nb_invalid*4 + 1 < nb_frames) {
        static const char ct_jpeg[] = "\r\nContent-Type: image/jpeg\r\n";
        int i;

        for (i=0; i<FFMIN(p->buf_size - (int)sizeof(ct_jpeg), 100); i++)
            if (!memcmp(p->buf + i, ct_jpeg, sizeof(ct_jpeg) - 1))
                return AVPROBE_SCORE_EXTENSION;

        if (nb_invalid == 0 && nb_frames > 2)
            return AVPROBE_SCORE_EXTENSION / 2;
        return AVPROBE_SCORE_EXTENSION / 4;
    }
    if (!nb_invalid && nb_frames)
        return AVPROBE_SCORE_EXTENSION / 4;

    return 0;
}

FF_DEF_RAWVIDEO_DEMUXER2(mjpeg, "raw MJPEG video", mjpeg_probe, "mjpg,mjpeg,mpo", AV_CODEC_ID_MJPEG, AVFMT_GENERIC_INDEX|AVFMT_NOTIMESTAMPS)
#endif