1/* 2 * Creative Voice File demuxer. 3 * Copyright (c) 2006 Aurelien Jacobs <aurel@gnuage.org> 4 * 5 * This file is part of FFmpeg. 6 * 7 * FFmpeg is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU Lesser General Public 9 * License as published by the Free Software Foundation; either 10 * version 2.1 of the License, or (at your option) any later version. 11 * 12 * FFmpeg is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 15 * Lesser General Public License for more details. 16 * 17 * You should have received a copy of the GNU Lesser General Public 18 * License along with FFmpeg; if not, write to the Free Software 19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 20 */ 21 22#include "libavutil/intreadwrite.h" 23#include "voc.h" 24 25 26static int voc_probe(AVProbeData *p) 27{ 28 int version, check; 29 30 if (memcmp(p->buf, ff_voc_magic, sizeof(ff_voc_magic) - 1)) 31 return 0; 32 version = AV_RL16(p->buf + 22); 33 check = AV_RL16(p->buf + 24); 34 if (~version + 0x1234 != check) 35 return 10; 36 37 return AVPROBE_SCORE_MAX; 38} 39 40static int voc_read_header(AVFormatContext *s, AVFormatParameters *ap) 41{ 42 VocDecContext *voc = s->priv_data; 43 ByteIOContext *pb = s->pb; 44 int header_size; 45 AVStream *st; 46 47 url_fskip(pb, 20); 48 header_size = get_le16(pb) - 22; 49 if (header_size != 4) { 50 av_log(s, AV_LOG_ERROR, "unknown header size: %d\n", header_size); 51 return AVERROR(ENOSYS); 52 } 53 url_fskip(pb, header_size); 54 st = av_new_stream(s, 0); 55 if (!st) 56 return AVERROR(ENOMEM); 57 st->codec->codec_type = AVMEDIA_TYPE_AUDIO; 58 59 voc->remaining_size = 0; 60 return 0; 61} 62 63int 64voc_get_packet(AVFormatContext *s, AVPacket *pkt, AVStream *st, int max_size) 65{ 66 VocDecContext *voc = s->priv_data; 67 AVCodecContext *dec = st->codec; 68 ByteIOContext *pb = s->pb; 69 VocType type; 70 int size; 71 int sample_rate = 0; 72 int channels = 1; 73 74 while (!voc->remaining_size) { 75 type = get_byte(pb); 76 if (type == VOC_TYPE_EOF) 77 return AVERROR(EIO); 78 voc->remaining_size = get_le24(pb); 79 if (!voc->remaining_size) { 80 if (url_is_streamed(s->pb)) 81 return AVERROR(EIO); 82 voc->remaining_size = url_fsize(pb) - url_ftell(pb); 83 } 84 max_size -= 4; 85 86 switch (type) { 87 case VOC_TYPE_VOICE_DATA: 88 dec->sample_rate = 1000000 / (256 - get_byte(pb)); 89 if (sample_rate) 90 dec->sample_rate = sample_rate; 91 dec->channels = channels; 92 dec->codec_id = ff_codec_get_id(ff_voc_codec_tags, get_byte(pb)); 93 dec->bits_per_coded_sample = av_get_bits_per_sample(dec->codec_id); 94 voc->remaining_size -= 2; 95 max_size -= 2; 96 channels = 1; 97 break; 98 99 case VOC_TYPE_VOICE_DATA_CONT: 100 break; 101 102 case VOC_TYPE_EXTENDED: 103 sample_rate = get_le16(pb); 104 get_byte(pb); 105 channels = get_byte(pb) + 1; 106 sample_rate = 256000000 / (channels * (65536 - sample_rate)); 107 voc->remaining_size = 0; 108 max_size -= 4; 109 break; 110 111 case VOC_TYPE_NEW_VOICE_DATA: 112 dec->sample_rate = get_le32(pb); 113 dec->bits_per_coded_sample = get_byte(pb); 114 dec->channels = get_byte(pb); 115 dec->codec_id = ff_codec_get_id(ff_voc_codec_tags, get_le16(pb)); 116 url_fskip(pb, 4); 117 voc->remaining_size -= 12; 118 max_size -= 12; 119 break; 120 121 default: 122 url_fskip(pb, voc->remaining_size); 123 max_size -= voc->remaining_size; 124 voc->remaining_size = 0; 125 break; 126 } 127 } 128 129 dec->bit_rate = dec->sample_rate * dec->bits_per_coded_sample; 130 131 if (max_size <= 0) 132 max_size = 2048; 133 size = FFMIN(voc->remaining_size, max_size); 134 voc->remaining_size -= size; 135 return av_get_packet(pb, pkt, size); 136} 137 138static int voc_read_packet(AVFormatContext *s, AVPacket *pkt) 139{ 140 return voc_get_packet(s, pkt, s->streams[0], 0); 141} 142 143AVInputFormat voc_demuxer = { 144 "voc", 145 NULL_IF_CONFIG_SMALL("Creative Voice file format"), 146 sizeof(VocDecContext), 147 voc_probe, 148 voc_read_header, 149 voc_read_packet, 150 .codec_tag=(const AVCodecTag* const []){ff_voc_codec_tags, 0}, 151}; 152