| 1 | /* |
| 2 | * ISS (.iss) file demuxer |
| 3 | * Copyright (c) 2008 Jaikrishnan Menon <realityman@gmx.net> |
| 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 | /** |
| 23 | * @file |
| 24 | * Funcom ISS file demuxer |
| 25 | * @author Jaikrishnan Menon |
| 26 | * @see http://wiki.multimedia.cx/index.php?title=FunCom_ISS |
| 27 | */ |
| 28 | |
| 29 | #include "libavutil/channel_layout.h" |
| 30 | #include "avformat.h" |
| 31 | #include "internal.h" |
| 32 | #include "libavutil/avstring.h" |
| 33 | |
| 34 | #define ISS_SIG "IMA_ADPCM_Sound" |
| 35 | #define ISS_SIG_LEN 15 |
| 36 | #define MAX_TOKEN_SIZE 20 |
| 37 | |
| 38 | typedef struct { |
| 39 | int packet_size; |
| 40 | int sample_start_pos; |
| 41 | } IssDemuxContext; |
| 42 | |
| 43 | static void get_token(AVIOContext *s, char *buf, int maxlen) |
| 44 | { |
| 45 | int i = 0; |
| 46 | char c; |
| 47 | |
| 48 | while ((c = avio_r8(s))) { |
| 49 | if(c == ' ') |
| 50 | break; |
| 51 | if (i < maxlen-1) |
| 52 | buf[i++] = c; |
| 53 | } |
| 54 | |
| 55 | if(!c) |
| 56 | avio_r8(s); |
| 57 | |
| 58 | buf[i] = 0; /* Ensure null terminated, but may be truncated */ |
| 59 | } |
| 60 | |
| 61 | static int iss_probe(AVProbeData *p) |
| 62 | { |
| 63 | if (strncmp(p->buf, ISS_SIG, ISS_SIG_LEN)) |
| 64 | return 0; |
| 65 | |
| 66 | return AVPROBE_SCORE_MAX; |
| 67 | } |
| 68 | |
| 69 | static av_cold int iss_read_header(AVFormatContext *s) |
| 70 | { |
| 71 | IssDemuxContext *iss = s->priv_data; |
| 72 | AVIOContext *pb = s->pb; |
| 73 | AVStream *st; |
| 74 | char token[MAX_TOKEN_SIZE]; |
| 75 | int stereo, rate_divisor; |
| 76 | |
| 77 | get_token(pb, token, sizeof(token)); //"IMA_ADPCM_Sound" |
| 78 | get_token(pb, token, sizeof(token)); //packet size |
| 79 | if (sscanf(token, "%d", &iss->packet_size) != 1) { |
| 80 | av_log(s, AV_LOG_ERROR, "Failed parsing packet size\n"); |
| 81 | return AVERROR_INVALIDDATA; |
| 82 | } |
| 83 | get_token(pb, token, sizeof(token)); //File ID |
| 84 | get_token(pb, token, sizeof(token)); //out size |
| 85 | get_token(pb, token, sizeof(token)); //stereo |
| 86 | if (sscanf(token, "%d", &stereo) != 1) { |
| 87 | av_log(s, AV_LOG_ERROR, "Failed parsing stereo flag\n"); |
| 88 | return AVERROR_INVALIDDATA; |
| 89 | } |
| 90 | get_token(pb, token, sizeof(token)); //Unknown1 |
| 91 | get_token(pb, token, sizeof(token)); //RateDivisor |
| 92 | if (sscanf(token, "%d", &rate_divisor) != 1) { |
| 93 | av_log(s, AV_LOG_ERROR, "Failed parsing rate_divisor\n"); |
| 94 | return AVERROR_INVALIDDATA; |
| 95 | } |
| 96 | get_token(pb, token, sizeof(token)); //Unknown2 |
| 97 | get_token(pb, token, sizeof(token)); //Version ID |
| 98 | get_token(pb, token, sizeof(token)); //Size |
| 99 | |
| 100 | if (iss->packet_size <= 0) { |
| 101 | av_log(s, AV_LOG_ERROR, "packet_size %d is invalid\n", iss->packet_size); |
| 102 | return AVERROR_INVALIDDATA; |
| 103 | } |
| 104 | |
| 105 | iss->sample_start_pos = avio_tell(pb); |
| 106 | |
| 107 | st = avformat_new_stream(s, NULL); |
| 108 | if (!st) |
| 109 | return AVERROR(ENOMEM); |
| 110 | st->codec->codec_type = AVMEDIA_TYPE_AUDIO; |
| 111 | st->codec->codec_id = AV_CODEC_ID_ADPCM_IMA_ISS; |
| 112 | if (stereo) { |
| 113 | st->codec->channels = 2; |
| 114 | st->codec->channel_layout = AV_CH_LAYOUT_STEREO; |
| 115 | } else { |
| 116 | st->codec->channels = 1; |
| 117 | st->codec->channel_layout = AV_CH_LAYOUT_MONO; |
| 118 | } |
| 119 | st->codec->sample_rate = 44100; |
| 120 | if(rate_divisor > 0) |
| 121 | st->codec->sample_rate /= rate_divisor; |
| 122 | st->codec->bits_per_coded_sample = 4; |
| 123 | st->codec->bit_rate = st->codec->channels * st->codec->sample_rate |
| 124 | * st->codec->bits_per_coded_sample; |
| 125 | st->codec->block_align = iss->packet_size; |
| 126 | avpriv_set_pts_info(st, 32, 1, st->codec->sample_rate); |
| 127 | |
| 128 | return 0; |
| 129 | } |
| 130 | |
| 131 | static int iss_read_packet(AVFormatContext *s, AVPacket *pkt) |
| 132 | { |
| 133 | IssDemuxContext *iss = s->priv_data; |
| 134 | int ret = av_get_packet(s->pb, pkt, iss->packet_size); |
| 135 | |
| 136 | if(ret != iss->packet_size) |
| 137 | return AVERROR(EIO); |
| 138 | |
| 139 | pkt->stream_index = 0; |
| 140 | pkt->pts = avio_tell(s->pb) - iss->sample_start_pos; |
| 141 | if(s->streams[0]->codec->channels > 0) |
| 142 | pkt->pts /= s->streams[0]->codec->channels*2; |
| 143 | return 0; |
| 144 | } |
| 145 | |
| 146 | AVInputFormat ff_iss_demuxer = { |
| 147 | .name = "iss", |
| 148 | .long_name = NULL_IF_CONFIG_SMALL("Funcom ISS"), |
| 149 | .priv_data_size = sizeof(IssDemuxContext), |
| 150 | .read_probe = iss_probe, |
| 151 | .read_header = iss_read_header, |
| 152 | .read_packet = iss_read_packet, |
| 153 | }; |