FFmpeg/libavformat/wvedec.c

/*
 * Copyright (c) 2015 Paul B Mahol
 *
 * 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 "avformat.h"
#include "demux.h"
#include "internal.h"
#include "pcm.h"

static int wve_probe(const AVProbeData *p)
{
    if (memcmp(p->buf, "ALawSoundFile**\0\017\020", 18) ||
        memcmp(p->buf + 22, "\0\0\0\1\0\0\0\0\0\0", 10))
        return 0;
    return AVPROBE_SCORE_MAX;
}

static int wve_read_header(AVFormatContext *s)
{
    AVStream *st;

    st = avformat_new_stream(s, NULL);
    if (!st)
        return AVERROR(ENOMEM);

    avio_skip(s->pb, 18);
    st->duration           = avio_rb32(s->pb);
    st->codecpar->codec_type  = AVMEDIA_TYPE_AUDIO;
    st->codecpar->codec_id    = AV_CODEC_ID_PCM_ALAW;
    st->codecpar->sample_rate = 8000;
    st->codecpar->ch_layout.nb_channels = 1;
    st->codecpar->bits_per_coded_sample = 8;
    st->codecpar->block_align = st->codecpar->bits_per_coded_sample *
                                st->codecpar->ch_layout.nb_channels / 8;
    avpriv_set_pts_info(st, 64, 1, st->codecpar->sample_rate);
    avio_skip(s->pb, 10);

    return 0;
}

const FFInputFormat ff_wve_demuxer = {
    .p.name         = "wve",
    .p.long_name    = NULL_IF_CONFIG_SMALL("Psion 3 audio"),
    .read_probe     = wve_probe,
    .read_header    = wve_read_header,
    .read_packet    = ff_pcm_read_packet,
    .read_seek      = ff_pcm_read_seek,
};