avio: avio_ prefixes for get_* functions
[libav.git] / libavformat / xa.c
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1/*
2 * Maxis XA (.xa) File Demuxer
3 * Copyright (c) 2008 Robert Marston
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/**
ba87f080 23 * @file
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24 * Maxis XA File Demuxer
25 * by Robert Marston (rmarston@gmail.com)
26 * for more information on the XA audio format see
27 * http://wiki.multimedia.cx/index.php?title=Maxis_XA
28 */
29
6a5d31ac 30#include "libavutil/intreadwrite.h"
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31#include "avformat.h"
32
33#define XA00_TAG MKTAG('X', 'A', 0, 0)
34#define XAI0_TAG MKTAG('X', 'A', 'I', 0)
35#define XAJ0_TAG MKTAG('X', 'A', 'J', 0)
36
37typedef struct MaxisXADemuxContext {
38 uint32_t out_size;
39 uint32_t sent_bytes;
40 uint32_t audio_frame_counter;
41} MaxisXADemuxContext;
42
43static int xa_probe(AVProbeData *p)
44{
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45 int channels, srate, bits_per_sample;
46 if (p->buf_size < 24)
47 return 0;
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48 switch(AV_RL32(p->buf)) {
49 case XA00_TAG:
50 case XAI0_TAG:
51 case XAJ0_TAG:
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52 break;
53 default:
54 return 0;
861c63a2 55 }
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56 channels = AV_RL16(p->buf + 10);
57 srate = AV_RL32(p->buf + 12);
58 bits_per_sample = AV_RL16(p->buf + 22);
59 if (!channels || channels > 8 || !srate || srate > 192000 ||
60 bits_per_sample < 4 || bits_per_sample > 32)
61 return 0;
62 return AVPROBE_SCORE_MAX/2;
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63}
64
65static int xa_read_header(AVFormatContext *s,
66 AVFormatParameters *ap)
67{
68 MaxisXADemuxContext *xa = s->priv_data;
ae628ec1 69 AVIOContext *pb = s->pb;
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70 AVStream *st;
71
72 /*Set up the XA Audio Decoder*/
73 st = av_new_stream(s, 0);
74 if (!st)
75 return AVERROR(ENOMEM);
76
72415b2a 77 st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
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78 st->codec->codec_id = CODEC_ID_ADPCM_EA_MAXIS_XA;
79 url_fskip(pb, 4); /* Skip the XA ID */
b7effd4e 80 xa->out_size = avio_rl32(pb);
861c63a2 81 url_fskip(pb, 2); /* Skip the tag */
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82 st->codec->channels = avio_rl16(pb);
83 st->codec->sample_rate = avio_rl32(pb);
861c63a2 84 /* Value in file is average byte rate*/
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85 st->codec->bit_rate = avio_rl32(pb) * 8;
86 st->codec->block_align = avio_rl16(pb);
87 st->codec->bits_per_coded_sample = avio_rl16(pb);
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88
89 av_set_pts_info(st, 64, 1, st->codec->sample_rate);
90
91 return 0;
92}
93
94static int xa_read_packet(AVFormatContext *s,
95 AVPacket *pkt)
96{
97 MaxisXADemuxContext *xa = s->priv_data;
98 AVStream *st = s->streams[0];
ae628ec1 99 AVIOContext *pb = s->pb;
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100 unsigned int packet_size;
101 int ret;
102
103 if(xa->sent_bytes > xa->out_size)
104 return AVERROR(EIO);
105 /* 1 byte header and 14 bytes worth of samples * number channels per block */
106 packet_size = 15*st->codec->channels;
107
108 ret = av_get_packet(pb, pkt, packet_size);
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109 if(ret < 0)
110 return ret;
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111
112 pkt->stream_index = st->index;
113 xa->sent_bytes += packet_size;
114 pkt->pts = xa->audio_frame_counter;
115 /* 14 bytes Samples per channel with 2 samples per byte */
116 xa->audio_frame_counter += 28 * st->codec->channels;
117
118 return ret;
119}
120
c6610a21 121AVInputFormat ff_xa_demuxer = {
861c63a2 122 "xa",
bde15e74 123 NULL_IF_CONFIG_SMALL("Maxis XA File Format"),
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124 sizeof(MaxisXADemuxContext),
125 xa_probe,
126 xa_read_header,
127 xa_read_packet,
128};