yading@11: /*
yading@11:  * Creative Voice File demuxer.
yading@11:  * Copyright (c) 2006  Aurelien Jacobs <aurel@gnuage.org>
yading@11:  *
yading@11:  * This file is part of FFmpeg.
yading@11:  *
yading@11:  * FFmpeg is free software; you can redistribute it and/or
yading@11:  * modify it under the terms of the GNU Lesser General Public
yading@11:  * License as published by the Free Software Foundation; either
yading@11:  * version 2.1 of the License, or (at your option) any later version.
yading@11:  *
yading@11:  * FFmpeg is distributed in the hope that it will be useful,
yading@11:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@11:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
yading@11:  * Lesser General Public License for more details.
yading@11:  *
yading@11:  * You should have received a copy of the GNU Lesser General Public
yading@11:  * License along with FFmpeg; if not, write to the Free Software
yading@11:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
yading@11:  */
yading@11: 
yading@11: #include "libavutil/intreadwrite.h"
yading@11: #include "voc.h"
yading@11: #include "internal.h"
yading@11: 
yading@11: 
yading@11: static int voc_probe(AVProbeData *p)
yading@11: {
yading@11:     int version, check;
yading@11: 
yading@11:     if (memcmp(p->buf, ff_voc_magic, sizeof(ff_voc_magic) - 1))
yading@11:         return 0;
yading@11:     version = AV_RL16(p->buf + 22);
yading@11:     check = AV_RL16(p->buf + 24);
yading@11:     if (~version + 0x1234 != check)
yading@11:         return 10;
yading@11: 
yading@11:     return AVPROBE_SCORE_MAX;
yading@11: }
yading@11: 
yading@11: static int voc_read_header(AVFormatContext *s)
yading@11: {
yading@11:     VocDecContext *voc = s->priv_data;
yading@11:     AVIOContext *pb = s->pb;
yading@11:     int header_size;
yading@11:     AVStream *st;
yading@11: 
yading@11:     avio_skip(pb, 20);
yading@11:     header_size = avio_rl16(pb) - 22;
yading@11:     if (header_size != 4) {
yading@11:         av_log(s, AV_LOG_ERROR, "unknown header size: %d\n", header_size);
yading@11:         return AVERROR(ENOSYS);
yading@11:     }
yading@11:     avio_skip(pb, header_size);
yading@11:     st = avformat_new_stream(s, NULL);
yading@11:     if (!st)
yading@11:         return AVERROR(ENOMEM);
yading@11:     st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
yading@11: 
yading@11:     voc->remaining_size = 0;
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: int
yading@11: ff_voc_get_packet(AVFormatContext *s, AVPacket *pkt, AVStream *st, int max_size)
yading@11: {
yading@11:     VocDecContext *voc = s->priv_data;
yading@11:     AVCodecContext *dec = st->codec;
yading@11:     AVIOContext *pb = s->pb;
yading@11:     VocType type;
yading@11:     int size, tmp_codec=-1;
yading@11:     int sample_rate = 0;
yading@11:     int channels = 1;
yading@11: 
yading@11:     while (!voc->remaining_size) {
yading@11:         type = avio_r8(pb);
yading@11:         if (type == VOC_TYPE_EOF)
yading@11:             return AVERROR(EIO);
yading@11:         voc->remaining_size = avio_rl24(pb);
yading@11:         if (!voc->remaining_size) {
yading@11:             if (!s->pb->seekable)
yading@11:                 return AVERROR(EIO);
yading@11:             voc->remaining_size = avio_size(pb) - avio_tell(pb);
yading@11:         }
yading@11:         max_size -= 4;
yading@11: 
yading@11:         switch (type) {
yading@11:         case VOC_TYPE_VOICE_DATA:
yading@11:             if (!dec->sample_rate) {
yading@11:                 dec->sample_rate = 1000000 / (256 - avio_r8(pb));
yading@11:                 if (sample_rate)
yading@11:                     dec->sample_rate = sample_rate;
yading@11:                 avpriv_set_pts_info(st, 64, 1, dec->sample_rate);
yading@11:             } else
yading@11:                 avio_skip(pb, 1);
yading@11:             dec->channels = channels;
yading@11:             tmp_codec = avio_r8(pb);
yading@11:             dec->bits_per_coded_sample = av_get_bits_per_sample(dec->codec_id);
yading@11:             voc->remaining_size -= 2;
yading@11:             max_size -= 2;
yading@11:             channels = 1;
yading@11:             break;
yading@11: 
yading@11:         case VOC_TYPE_VOICE_DATA_CONT:
yading@11:             break;
yading@11: 
yading@11:         case VOC_TYPE_EXTENDED:
yading@11:             sample_rate = avio_rl16(pb);
yading@11:             avio_r8(pb);
yading@11:             channels = avio_r8(pb) + 1;
yading@11:             sample_rate = 256000000 / (channels * (65536 - sample_rate));
yading@11:             voc->remaining_size = 0;
yading@11:             max_size -= 4;
yading@11:             break;
yading@11: 
yading@11:         case VOC_TYPE_NEW_VOICE_DATA:
yading@11:             if (!dec->sample_rate) {
yading@11:                 dec->sample_rate = avio_rl32(pb);
yading@11:                 avpriv_set_pts_info(st, 64, 1, dec->sample_rate);
yading@11:             } else
yading@11:                 avio_skip(pb, 4);
yading@11:             dec->bits_per_coded_sample = avio_r8(pb);
yading@11:             dec->channels = avio_r8(pb);
yading@11:             tmp_codec = avio_rl16(pb);
yading@11:             avio_skip(pb, 4);
yading@11:             voc->remaining_size -= 12;
yading@11:             max_size -= 12;
yading@11:             break;
yading@11: 
yading@11:         default:
yading@11:             avio_skip(pb, voc->remaining_size);
yading@11:             max_size -= voc->remaining_size;
yading@11:             voc->remaining_size = 0;
yading@11:             break;
yading@11:         }
yading@11:     }
yading@11: 
yading@11:     if (tmp_codec >= 0) {
yading@11:         tmp_codec = ff_codec_get_id(ff_voc_codec_tags, tmp_codec);
yading@11:         if (dec->codec_id == AV_CODEC_ID_NONE)
yading@11:             dec->codec_id = tmp_codec;
yading@11:         else if (dec->codec_id != tmp_codec)
yading@11:             av_log(s, AV_LOG_WARNING, "Ignoring mid-stream change in audio codec\n");
yading@11:         if (dec->codec_id == AV_CODEC_ID_NONE) {
yading@11:             if (s->audio_codec_id == AV_CODEC_ID_NONE) {
yading@11:                 av_log(s, AV_LOG_ERROR, "unknown codec tag\n");
yading@11:                 return AVERROR(EINVAL);
yading@11:             }
yading@11:             av_log(s, AV_LOG_WARNING, "unknown codec tag\n");
yading@11:         }
yading@11:     }
yading@11: 
yading@11:     dec->bit_rate = dec->sample_rate * dec->channels * dec->bits_per_coded_sample;
yading@11: 
yading@11:     if (max_size <= 0)
yading@11:         max_size = 2048;
yading@11:     size = FFMIN(voc->remaining_size, max_size);
yading@11:     voc->remaining_size -= size;
yading@11:     return av_get_packet(pb, pkt, size);
yading@11: }
yading@11: 
yading@11: static int voc_read_packet(AVFormatContext *s, AVPacket *pkt)
yading@11: {
yading@11:     return ff_voc_get_packet(s, pkt, s->streams[0], 0);
yading@11: }
yading@11: 
yading@11: AVInputFormat ff_voc_demuxer = {
yading@11:     .name           = "voc",
yading@11:     .long_name      = NULL_IF_CONFIG_SMALL("Creative Voice"),
yading@11:     .priv_data_size = sizeof(VocDecContext),
yading@11:     .read_probe     = voc_probe,
yading@11:     .read_header    = voc_read_header,
yading@11:     .read_packet    = voc_read_packet,
yading@11:     .codec_tag      = (const AVCodecTag* const []){ ff_voc_codec_tags, 0 },
yading@11: };