blob: 9f748f2bc3b170b82f1dc811269fa2cddfa14a02
1 | /* |
2 | * Linux audio play interface |
3 | * Copyright (c) 2000, 2001 Fabrice Bellard |
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 | #include "config.h" |
23 | |
24 | #include <stdint.h> |
25 | |
26 | #if HAVE_SOUNDCARD_H |
27 | #include <soundcard.h> |
28 | #else |
29 | #include <sys/soundcard.h> |
30 | #endif |
31 | |
32 | #if HAVE_UNISTD_H |
33 | #include <unistd.h> |
34 | #endif |
35 | #include <fcntl.h> |
36 | #include <sys/ioctl.h> |
37 | |
38 | #include "libavutil/internal.h" |
39 | #include "libavutil/opt.h" |
40 | #include "libavutil/time.h" |
41 | |
42 | #include "libavcodec/avcodec.h" |
43 | |
44 | #include "avdevice.h" |
45 | #include "libavformat/internal.h" |
46 | |
47 | #include "oss.h" |
48 | |
49 | static int audio_read_header(AVFormatContext *s1) |
50 | { |
51 | OSSAudioData *s = s1->priv_data; |
52 | AVStream *st; |
53 | int ret; |
54 | |
55 | st = avformat_new_stream(s1, NULL); |
56 | if (!st) { |
57 | return AVERROR(ENOMEM); |
58 | } |
59 | |
60 | ret = ff_oss_audio_open(s1, 0, s1->filename); |
61 | if (ret < 0) { |
62 | return AVERROR(EIO); |
63 | } |
64 | |
65 | /* take real parameters */ |
66 | st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO; |
67 | st->codecpar->codec_id = s->codec_id; |
68 | st->codecpar->sample_rate = s->sample_rate; |
69 | st->codecpar->channels = s->channels; |
70 | |
71 | avpriv_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */ |
72 | return 0; |
73 | } |
74 | |
75 | static int audio_read_packet(AVFormatContext *s1, AVPacket *pkt) |
76 | { |
77 | OSSAudioData *s = s1->priv_data; |
78 | int ret, bdelay; |
79 | int64_t cur_time; |
80 | struct audio_buf_info abufi; |
81 | |
82 | if ((ret=av_new_packet(pkt, s->frame_size)) < 0) |
83 | return ret; |
84 | |
85 | ret = read(s->fd, pkt->data, pkt->size); |
86 | if (ret <= 0){ |
87 | av_packet_unref(pkt); |
88 | pkt->size = 0; |
89 | if (ret<0) return AVERROR(errno); |
90 | else return AVERROR_EOF; |
91 | } |
92 | pkt->size = ret; |
93 | |
94 | /* compute pts of the start of the packet */ |
95 | cur_time = av_gettime(); |
96 | bdelay = ret; |
97 | if (ioctl(s->fd, SNDCTL_DSP_GETISPACE, &abufi) == 0) { |
98 | bdelay += abufi.bytes; |
99 | } |
100 | /* subtract time represented by the number of bytes in the audio fifo */ |
101 | cur_time -= (bdelay * 1000000LL) / (s->sample_rate * s->channels); |
102 | |
103 | /* convert to wanted units */ |
104 | pkt->pts = cur_time; |
105 | |
106 | if (s->flip_left && s->channels == 2) { |
107 | int i; |
108 | short *p = (short *) pkt->data; |
109 | |
110 | for (i = 0; i < ret; i += 4) { |
111 | *p = ~*p; |
112 | p += 2; |
113 | } |
114 | } |
115 | return 0; |
116 | } |
117 | |
118 | static int audio_read_close(AVFormatContext *s1) |
119 | { |
120 | OSSAudioData *s = s1->priv_data; |
121 | |
122 | ff_oss_audio_close(s); |
123 | return 0; |
124 | } |
125 | |
126 | static const AVOption options[] = { |
127 | { "sample_rate", "", offsetof(OSSAudioData, sample_rate), AV_OPT_TYPE_INT, {.i64 = 48000}, 1, INT_MAX, AV_OPT_FLAG_DECODING_PARAM }, |
128 | { "channels", "", offsetof(OSSAudioData, channels), AV_OPT_TYPE_INT, {.i64 = 2}, 1, INT_MAX, AV_OPT_FLAG_DECODING_PARAM }, |
129 | { NULL }, |
130 | }; |
131 | |
132 | static const AVClass oss_demuxer_class = { |
133 | .class_name = "OSS demuxer", |
134 | .item_name = av_default_item_name, |
135 | .option = options, |
136 | .version = LIBAVUTIL_VERSION_INT, |
137 | .category = AV_CLASS_CATEGORY_DEVICE_AUDIO_INPUT, |
138 | }; |
139 | |
140 | AVInputFormat ff_oss_demuxer = { |
141 | .name = "oss", |
142 | .long_name = NULL_IF_CONFIG_SMALL("OSS (Open Sound System) capture"), |
143 | .priv_data_size = sizeof(OSSAudioData), |
144 | .read_header = audio_read_header, |
145 | .read_packet = audio_read_packet, |
146 | .read_close = audio_read_close, |
147 | .flags = AVFMT_NOFILE, |
148 | .priv_class = &oss_demuxer_class, |
149 | }; |
150 |