1/*
2 * ACT file format demuxer
3 * Copyright (c) 2007-2008 Vladimir Voroshilov
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#include "avformat.h"
22#include "riff.h"
23#include "internal.h"
24#include "libavcodec/get_bits.h"
25
26#define CHUNK_SIZE 512
27#define RIFF_TAG MKTAG('R','I','F','F')
28#define WAVE_TAG MKTAG('W','A','V','E')
29
30typedef struct{
31    int bytes_left_in_chunk;
32    uint8_t audio_buffer[22];///< temporary buffer for ACT frame
33    char second_packet;      ///< 1 - if temporary buffer contains valid (second) G.729 packet
34} ACTContext;
35
36static int probe(AVProbeData *p)
37{
38    int i;
39
40    if ((AV_RL32(&p->buf[0]) != RIFF_TAG) ||
41        (AV_RL32(&p->buf[8]) != WAVE_TAG) ||
42        (AV_RL32(&p->buf[16]) != 16))
43    return 0;
44
45    //We can't be sure that this is ACT and not regular WAV
46    if (p->buf_size<512)
47        return 0;
48
49    for(i=44; i<256; i++)
50        if(p->buf[i])
51            return 0;
52
53    if(p->buf[256]!=0x84)
54        return 0;
55
56    for(i=264; i<512; i++)
57        if(p->buf[i])
58            return 0;
59
60    return AVPROBE_SCORE_MAX;
61}
62
63static int read_header(AVFormatContext *s)
64{
65    ACTContext* ctx = s->priv_data;
66    AVIOContext *pb = s->pb;
67    int size;
68    AVStream* st;
69
70    int min,sec,msec;
71
72    st = avformat_new_stream(s, NULL);
73    if (!st)
74        return AVERROR(ENOMEM);
75
76    avio_skip(pb, 16);
77    size=avio_rl32(pb);
78    ff_get_wav_header(pb, st->codec, size);
79
80    /*
81      8000Hz (Fine-rec) file format has 10 bytes long
82      packets with 10ms of sound data in them
83    */
84    if (st->codec->sample_rate != 8000) {
85        av_log(s, AV_LOG_ERROR, "Sample rate %d is not supported.\n", st->codec->sample_rate);
86        return AVERROR_INVALIDDATA;
87    }
88
89    st->codec->frame_size=80;
90    st->codec->channels=1;
91    avpriv_set_pts_info(st, 64, 1, 100);
92
93    st->codec->codec_id=AV_CODEC_ID_G729;
94
95    avio_seek(pb, 257, SEEK_SET);
96    msec=avio_rl16(pb);
97    sec=avio_r8(pb);
98    min=avio_rl32(pb);
99
100    st->duration = av_rescale(1000*(min*60+sec)+msec, st->codec->sample_rate, 1000 * st->codec->frame_size);
101
102    ctx->bytes_left_in_chunk=CHUNK_SIZE;
103
104    avio_seek(pb, 512, SEEK_SET);
105
106    return 0;
107}
108
109
110static int read_packet(AVFormatContext *s,
111                          AVPacket *pkt)
112{
113    ACTContext *ctx = s->priv_data;
114    AVIOContext *pb = s->pb;
115    int ret;
116    int frame_size=s->streams[0]->codec->sample_rate==8000?10:22;
117
118
119    if(s->streams[0]->codec->sample_rate==8000)
120        ret=av_new_packet(pkt, 10);
121    else
122        ret=av_new_packet(pkt, 11);
123
124    if(ret)
125        return ret;
126
127    if(s->streams[0]->codec->sample_rate==4400 && !ctx->second_packet)
128    {
129        ret = avio_read(pb, ctx->audio_buffer, frame_size);
130
131        if(ret<0)
132            return ret;
133        if(ret!=frame_size)
134            return AVERROR(EIO);
135
136        pkt->data[0]=ctx->audio_buffer[11];
137        pkt->data[1]=ctx->audio_buffer[0];
138        pkt->data[2]=ctx->audio_buffer[12];
139        pkt->data[3]=ctx->audio_buffer[1];
140        pkt->data[4]=ctx->audio_buffer[13];
141        pkt->data[5]=ctx->audio_buffer[2];
142        pkt->data[6]=ctx->audio_buffer[14];
143        pkt->data[7]=ctx->audio_buffer[3];
144        pkt->data[8]=ctx->audio_buffer[15];
145        pkt->data[9]=ctx->audio_buffer[4];
146        pkt->data[10]=ctx->audio_buffer[16];
147
148        ctx->second_packet=1;
149    }
150    else if(s->streams[0]->codec->sample_rate==4400 && ctx->second_packet)
151    {
152        pkt->data[0]=ctx->audio_buffer[5];
153        pkt->data[1]=ctx->audio_buffer[17];
154        pkt->data[2]=ctx->audio_buffer[6];
155        pkt->data[3]=ctx->audio_buffer[18];
156        pkt->data[4]=ctx->audio_buffer[7];
157        pkt->data[5]=ctx->audio_buffer[19];
158        pkt->data[6]=ctx->audio_buffer[8];
159        pkt->data[7]=ctx->audio_buffer[20];
160        pkt->data[8]=ctx->audio_buffer[9];
161        pkt->data[9]=ctx->audio_buffer[21];
162        pkt->data[10]=ctx->audio_buffer[10];
163
164        ctx->second_packet=0;
165    }
166    else // 8000 Hz
167    {
168        ret = avio_read(pb, ctx->audio_buffer, frame_size);
169
170        if(ret<0)
171            return ret;
172        if(ret!=frame_size)
173            return AVERROR(EIO);
174
175        pkt->data[0]=ctx->audio_buffer[5];
176        pkt->data[1]=ctx->audio_buffer[0];
177        pkt->data[2]=ctx->audio_buffer[6];
178        pkt->data[3]=ctx->audio_buffer[1];
179        pkt->data[4]=ctx->audio_buffer[7];
180        pkt->data[5]=ctx->audio_buffer[2];
181        pkt->data[6]=ctx->audio_buffer[8];
182        pkt->data[7]=ctx->audio_buffer[3];
183        pkt->data[8]=ctx->audio_buffer[9];
184        pkt->data[9]=ctx->audio_buffer[4];
185    }
186
187    ctx->bytes_left_in_chunk -= frame_size;
188
189    if(ctx->bytes_left_in_chunk < frame_size)
190    {
191        avio_skip(pb, ctx->bytes_left_in_chunk);
192        ctx->bytes_left_in_chunk=CHUNK_SIZE;
193    }
194
195    pkt->duration=1;
196
197    return ret;
198}
199
200AVInputFormat ff_act_demuxer = {
201    .name           = "act",
202    .long_name      = "ACT Voice file format",
203    .priv_data_size = sizeof(ACTContext),
204    .read_probe     = probe,
205    .read_header    = read_header,
206    .read_packet    = read_packet,
207};
208