| /* |
| * ISS (.iss) file demuxer |
| * Copyright (c) 2008 Jaikrishnan Menon <realityman@gmx.net> |
| * |
| * 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 |
| */ |
| |
| /** |
| * @file |
| * Funcom ISS file demuxer |
| * @author Jaikrishnan Menon |
| * for more information on the .iss file format, visit: |
| * http://wiki.multimedia.cx/index.php?title=FunCom_ISS |
| */ |
| |
| #include "avformat.h" |
| #include "libavutil/avstring.h" |
| |
| #define ISS_SIG "IMA_ADPCM_Sound" |
| #define ISS_SIG_LEN 15 |
| #define MAX_TOKEN_SIZE 20 |
| |
| typedef struct { |
| int packet_size; |
| int sample_start_pos; |
| } IssDemuxContext; |
| |
| static void get_token(ByteIOContext *s, char *buf, int maxlen) |
| { |
| int i = 0; |
| char c; |
| |
| while ((c = get_byte(s))) { |
| if(c == ' ') |
| break; |
| if (i < maxlen-1) |
| buf[i++] = c; |
| } |
| |
| if(!c) |
| get_byte(s); |
| |
| buf[i] = 0; /* Ensure null terminated, but may be truncated */ |
| } |
| |
| static int iss_probe(AVProbeData *p) |
| { |
| if (strncmp(p->buf, ISS_SIG, ISS_SIG_LEN)) |
| return 0; |
| |
| return AVPROBE_SCORE_MAX; |
| } |
| |
| static av_cold int iss_read_header(AVFormatContext *s, AVFormatParameters *ap) |
| { |
| IssDemuxContext *iss = s->priv_data; |
| ByteIOContext *pb = s->pb; |
| AVStream *st; |
| char token[MAX_TOKEN_SIZE]; |
| int stereo, rate_divisor; |
| |
| get_token(pb, token, sizeof(token)); //"IMA_ADPCM_Sound" |
| get_token(pb, token, sizeof(token)); //packet size |
| sscanf(token, "%d", &iss->packet_size); |
| get_token(pb, token, sizeof(token)); //File ID |
| get_token(pb, token, sizeof(token)); //out size |
| get_token(pb, token, sizeof(token)); //stereo |
| sscanf(token, "%d", &stereo); |
| get_token(pb, token, sizeof(token)); //Unknown1 |
| get_token(pb, token, sizeof(token)); //RateDivisor |
| sscanf(token, "%d", &rate_divisor); |
| get_token(pb, token, sizeof(token)); //Unknown2 |
| get_token(pb, token, sizeof(token)); //Version ID |
| get_token(pb, token, sizeof(token)); //Size |
| |
| iss->sample_start_pos = url_ftell(pb); |
| |
| st = av_new_stream(s, 0); |
| if (!st) |
| return AVERROR(ENOMEM); |
| st->codec->codec_type = AVMEDIA_TYPE_AUDIO; |
| st->codec->codec_id = CODEC_ID_ADPCM_IMA_ISS; |
| st->codec->channels = stereo ? 2 : 1; |
| st->codec->sample_rate = 44100; |
| if(rate_divisor > 0) |
| st->codec->sample_rate /= rate_divisor; |
| st->codec->bits_per_coded_sample = 4; |
| st->codec->bit_rate = st->codec->channels * st->codec->sample_rate |
| * st->codec->bits_per_coded_sample; |
| st->codec->block_align = iss->packet_size; |
| av_set_pts_info(st, 32, 1, st->codec->sample_rate); |
| |
| return 0; |
| } |
| |
| static int iss_read_packet(AVFormatContext *s, AVPacket *pkt) |
| { |
| IssDemuxContext *iss = s->priv_data; |
| int ret = av_get_packet(s->pb, pkt, iss->packet_size); |
| |
| if(ret != iss->packet_size) |
| return AVERROR(EIO); |
| |
| pkt->stream_index = 0; |
| pkt->pts = url_ftell(s->pb) - iss->sample_start_pos; |
| if(s->streams[0]->codec->channels > 0) |
| pkt->pts /= s->streams[0]->codec->channels*2; |
| return 0; |
| } |
| |
| AVInputFormat iss_demuxer = { |
| "ISS", |
| NULL_IF_CONFIG_SMALL("Funcom ISS format"), |
| sizeof(IssDemuxContext), |
| iss_probe, |
| iss_read_header, |
| iss_read_packet, |
| }; |
| |