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2ba45a60 DM |
1 | /* |
2 | * G.729 bit format muxer and 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 "internal.h" | |
23 | #include "libavcodec/get_bits.h" | |
24 | #include "libavcodec/put_bits.h" | |
25 | ||
26 | #define MAX_FRAME_SIZE 10 | |
27 | ||
28 | #define SYNC_WORD 0x6b21 | |
29 | #define BIT_0 0x7f | |
30 | #define BIT_1 0x81 | |
31 | ||
32 | static int probe(AVProbeData *p) | |
33 | { | |
34 | int i, j; | |
35 | ||
36 | if(p->buf_size < 0x40) | |
37 | return 0; | |
38 | ||
39 | for(i=0; i+3<p->buf_size && i< 10*0x50; ){ | |
40 | if(AV_RL16(&p->buf[0]) != SYNC_WORD) | |
41 | return 0; | |
42 | j=AV_RL16(&p->buf[2]); | |
43 | if(j!=0x40 && j!=0x50) | |
44 | return 0; | |
45 | i+=j; | |
46 | } | |
47 | return AVPROBE_SCORE_EXTENSION; | |
48 | } | |
49 | ||
50 | static int read_header(AVFormatContext *s) | |
51 | { | |
52 | AVStream* st; | |
53 | ||
54 | st=avformat_new_stream(s, NULL); | |
55 | if (!st) | |
56 | return AVERROR(ENOMEM); | |
57 | ||
58 | st->codec->codec_type = AVMEDIA_TYPE_AUDIO; | |
59 | st->codec->codec_id=AV_CODEC_ID_G729; | |
60 | st->codec->sample_rate=8000; | |
61 | st->codec->block_align = 16; | |
62 | st->codec->channels=1; | |
63 | ||
64 | avpriv_set_pts_info(st, 64, 1, 100); | |
65 | return 0; | |
66 | } | |
67 | ||
68 | static int read_packet(AVFormatContext *s, | |
69 | AVPacket *pkt) | |
70 | { | |
71 | AVIOContext *pb = s->pb; | |
72 | PutBitContext pbo; | |
73 | uint16_t buf[8 * MAX_FRAME_SIZE + 2]; | |
74 | int packet_size; | |
75 | uint16_t* src=buf; | |
76 | int i, j, ret; | |
77 | int64_t pos= avio_tell(pb); | |
78 | ||
79 | if(avio_feof(pb)) | |
80 | return AVERROR_EOF; | |
81 | ||
82 | avio_rl16(pb); // sync word | |
83 | packet_size = avio_rl16(pb) / 8; | |
84 | if(packet_size > MAX_FRAME_SIZE) | |
85 | return AVERROR_INVALIDDATA; | |
86 | ||
87 | ret = avio_read(pb, (uint8_t*)buf, (8 * packet_size) * sizeof(uint16_t)); | |
88 | if(ret<0) | |
89 | return ret; | |
90 | if(ret != 8 * packet_size * sizeof(uint16_t)) | |
91 | return AVERROR(EIO); | |
92 | ||
93 | if (av_new_packet(pkt, packet_size) < 0) | |
94 | return AVERROR(ENOMEM); | |
95 | ||
96 | init_put_bits(&pbo, pkt->data, packet_size); | |
97 | for(j=0; j < packet_size; j++) | |
98 | for(i=0; i<8;i++) | |
99 | put_bits(&pbo,1, AV_RL16(src++) == BIT_1 ? 1 : 0); | |
100 | ||
101 | flush_put_bits(&pbo); | |
102 | ||
103 | pkt->duration=1; | |
104 | pkt->pos = pos; | |
105 | return 0; | |
106 | } | |
107 | ||
108 | AVInputFormat ff_bit_demuxer = { | |
109 | .name = "bit", | |
110 | .long_name = NULL_IF_CONFIG_SMALL("G.729 BIT file format"), | |
111 | .read_probe = probe, | |
112 | .read_header = read_header, | |
113 | .read_packet = read_packet, | |
114 | .extensions = "bit", | |
115 | }; | |
116 | ||
117 | #if CONFIG_MUXERS | |
118 | static int write_header(AVFormatContext *s) | |
119 | { | |
120 | AVCodecContext *enc = s->streams[0]->codec; | |
121 | ||
122 | enc->codec_id = AV_CODEC_ID_G729; | |
123 | enc->channels = 1; | |
124 | enc->bits_per_coded_sample = 16; | |
125 | enc->block_align = (enc->bits_per_coded_sample * enc->channels) >> 3; | |
126 | ||
127 | return 0; | |
128 | } | |
129 | ||
130 | static int write_packet(AVFormatContext *s, AVPacket *pkt) | |
131 | { | |
132 | AVIOContext *pb = s->pb; | |
133 | GetBitContext gb; | |
134 | int i; | |
135 | ||
136 | avio_wl16(pb, SYNC_WORD); | |
137 | avio_wl16(pb, 8 * 10); | |
138 | ||
139 | init_get_bits(&gb, pkt->data, 8*10); | |
140 | for(i=0; i< 8 * 10; i++) | |
141 | avio_wl16(pb, get_bits1(&gb) ? BIT_1 : BIT_0); | |
142 | ||
143 | return 0; | |
144 | } | |
145 | ||
146 | AVOutputFormat ff_bit_muxer = { | |
147 | .name = "bit", | |
148 | .long_name = NULL_IF_CONFIG_SMALL("G.729 BIT file format"), | |
149 | .mime_type = "audio/bit", | |
150 | .extensions = "bit", | |
151 | .audio_codec = AV_CODEC_ID_G729, | |
152 | .video_codec = AV_CODEC_ID_NONE, | |
153 | .write_header = write_header, | |
154 | .write_packet = write_packet, | |
155 | }; | |
156 | #endif |