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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 
30 typedef 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 
probe(const AVProbeData * p)36 static int probe(const 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 
read_header(AVFormatContext * s)63 static 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(s, pb, st->codecpar, size, 0);
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->codecpar->sample_rate != 8000) {
85         av_log(s, AV_LOG_ERROR, "Sample rate %d is not supported.\n", st->codecpar->sample_rate);
86         return AVERROR_INVALIDDATA;
87     }
88 
89     st->codecpar->frame_size=80;
90     st->codecpar->channels=1;
91     avpriv_set_pts_info(st, 64, 1, 100);
92 
93     st->codecpar->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->codecpar->sample_rate, 1000 * st->codecpar->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 
read_packet(AVFormatContext * s,AVPacket * pkt)110 static 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]->codecpar->sample_rate==8000?10:22;
117 
118 
119     if(s->streams[0]->codecpar->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]->codecpar->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]->codecpar->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 
200 AVInputFormat 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