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ffmpeg / libavformat / iff.c @ d7fb5a18

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1 3a027f5e Jai Menon
/*
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 * IFF (.iff) file demuxer
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 * Copyright (c) 2008 Jaikrishnan Menon <realityman@gmx.net>
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 *
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 * This file is part of FFmpeg.
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 *
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 * FFmpeg is free software; you can redistribute it and/or
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 * modify it under the terms of the GNU Lesser General Public
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 * License as published by the Free Software Foundation; either
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 * version 2.1 of the License, or (at your option) any later version.
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 *
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 * FFmpeg is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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 * Lesser General Public License for more details.
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 *
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 * You should have received a copy of the GNU Lesser General Public
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 * License along with FFmpeg; if not, write to the Free Software
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 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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 */
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/**
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 * @file iff.c
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 * IFF file demuxer
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 * by Jaikrishnan Menon
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 * for more information on the .iff file format, visit:
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 * http://wiki.multimedia.cx/index.php?title=IFF
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 */
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#include "avformat.h"
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#define ID_8SVX       MKTAG('8','S','V','X')
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#define ID_VHDR       MKTAG('V','H','D','R')
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#define ID_ATAK       MKTAG('A','T','A','K')
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#define ID_RLSE       MKTAG('R','L','S','E')
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#define ID_CHAN       MKTAG('C','H','A','N')
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#define ID_FORM       MKTAG('F','O','R','M')
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#define ID_ANNO       MKTAG('A','N','N','O')
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#define ID_AUTH       MKTAG('A','U','T','H')
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#define ID_CHRS       MKTAG('C','H','R','S')
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#define ID_COPYRIGHT  MKTAG('(','c',')',' ')
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#define ID_CSET       MKTAG('C','S','E','T')
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#define ID_FVER       MKTAG('F','V','E','R')
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#define ID_NAME       MKTAG('N','A','M','E')
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#define ID_TEXT       MKTAG('T','E','X','T')
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#define ID_BODY       MKTAG('B','O','D','Y')
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#define LEFT    2
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#define RIGHT   4
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#define STEREO  6
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#define PACKET_SIZE 1024
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typedef enum {COMP_NONE, COMP_FIB, COMP_EXP} svx8_compression_type;
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typedef struct {
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    uint32_t  body_size;
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    uint32_t  sent_bytes;
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    uint32_t  audio_frame_count;
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} IffDemuxContext;
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static void interleave_stereo(const uint8_t *src, uint8_t *dest, int size)
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{
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    uint8_t *end = dest + size;
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    size = size>>1;
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    while(dest < end) {
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        *dest++ = *src;
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        *dest++ = *(src+size);
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        src++;
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    }
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}
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static int iff_probe(AVProbeData *p)
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{
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    const uint8_t *d = p->buf;
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    if ( AV_RL32(d)   == ID_FORM &&
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         AV_RL32(d+8) == ID_8SVX)
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        return AVPROBE_SCORE_MAX;
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    return 0;
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}
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static int iff_read_header(AVFormatContext *s,
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                           AVFormatParameters *ap)
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{
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    IffDemuxContext *iff = s->priv_data;
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    ByteIOContext *pb = s->pb;
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    AVStream *st;
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    uint32_t chunk_id, data_size;
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    int padding, done = 0;
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    st = av_new_stream(s, 0);
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    if (!st)
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      return AVERROR(ENOMEM);
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    st->codec->channels = 1;
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    url_fskip(pb, 12);
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    while(!done && !url_feof(pb)) {
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        chunk_id = get_le32(pb);
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        data_size = get_be32(pb);
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        padding = data_size & 1;
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        switch(chunk_id) {
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        case ID_VHDR:
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            url_fskip(pb, 12);
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            st->codec->sample_rate = get_be16(pb);
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            url_fskip(pb, 1);
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            st->codec->codec_tag = get_byte(pb);
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            url_fskip(pb, 4);
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            break;
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        case ID_BODY:
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            iff->body_size = data_size;
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            done = 1;
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            break;
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        case ID_CHAN:
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            st->codec->channels = (get_be32(pb) < 6) ? 1 : 2;
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            break;
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        default:
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            url_fseek(pb, data_size + padding, SEEK_CUR);
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            break;
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        }
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    }
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    if(!st->codec->sample_rate)
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        return AVERROR_INVALIDDATA;
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    av_set_pts_info(st, 32, 1, st->codec->sample_rate);
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    st->codec->codec_type = CODEC_TYPE_AUDIO;
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    switch(st->codec->codec_tag) {
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    case COMP_NONE:
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        st->codec->codec_id = CODEC_ID_PCM_S8;
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        break;
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    case COMP_FIB:
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        st->codec->codec_id = CODEC_ID_8SVX_FIB;
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        break;
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    case COMP_EXP:
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        st->codec->codec_id = CODEC_ID_8SVX_EXP;
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        break;
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    default:
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        av_log(s, AV_LOG_ERROR, "iff: unknown compression method\n");
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        return -1;
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    }
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    st->codec->bits_per_coded_sample = 8;
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    st->codec->bit_rate = st->codec->channels * st->codec->sample_rate * st->codec->bits_per_coded_sample;
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    st->codec->block_align = st->codec->channels * st->codec->bits_per_coded_sample;
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    return 0;
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}
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static int iff_read_packet(AVFormatContext *s,
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                           AVPacket *pkt)
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{
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    IffDemuxContext *iff = s->priv_data;
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    ByteIOContext *pb = s->pb;
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    int ret;
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    if(iff->sent_bytes > iff->body_size)
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        return AVERROR(EIO);
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    if(s->streams[0]->codec->channels == 2) {
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        uint8_t sample_buffer[PACKET_SIZE];
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        ret = get_buffer(pb, sample_buffer, PACKET_SIZE);
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        if(av_new_packet(pkt, PACKET_SIZE) < 0) {
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            av_log(s, AV_LOG_ERROR, "iff: cannot allocate packet \n");
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            return AVERROR(ENOMEM);
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        }
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        interleave_stereo(sample_buffer, pkt->data, PACKET_SIZE);
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    }
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    else {
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        ret = av_get_packet(pb, pkt, PACKET_SIZE);
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    }
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    if(iff->sent_bytes == 0)
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        pkt->flags |= PKT_FLAG_KEY;
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    iff->sent_bytes += PACKET_SIZE;
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    pkt->stream_index = 0;
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    pkt->pts = iff->audio_frame_count;
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    iff->audio_frame_count += ret / s->streams[0]->codec->channels;
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    return ret;
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}
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AVInputFormat iff_demuxer = {
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    "IFF",
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    NULL_IF_CONFIG_SMALL("IFF format"),
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    sizeof(IffDemuxContext),
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    iff_probe,
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    iff_read_header,
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    iff_read_packet,
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};