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nistspheredec.c
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1 /*
2  * NIST Sphere demuxer
3  * Copyright (c) 2012 Paul B Mahol
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 "libavutil/avstring.h"
23 #include "libavutil/intreadwrite.h"
24 #include "avformat.h"
25 #include "internal.h"
26 #include "pcm.h"
27 
28 static int nist_probe(AVProbeData *p)
29 {
30  if (AV_RL64(p->buf) == AV_RL64("NIST_1A\x0a"))
31  return AVPROBE_SCORE_MAX;
32  return 0;
33 }
34 
36 {
37  char buffer[32], coding[32] = "pcm", format[32] = "01";
38  int bps = 0, be = 0;
39  int32_t header_size;
40  AVStream *st;
41 
42  st = avformat_new_stream(s, NULL);
43  if (!st)
44  return AVERROR(ENOMEM);
45 
47 
48  ff_get_line(s->pb, buffer, sizeof(buffer));
49  ff_get_line(s->pb, buffer, sizeof(buffer));
50  sscanf(buffer, "%"SCNd32, &header_size);
51  if (header_size <= 0)
52  return AVERROR_INVALIDDATA;
53 
54  while (!url_feof(s->pb)) {
55  ff_get_line(s->pb, buffer, sizeof(buffer));
56 
57  if (avio_tell(s->pb) >= header_size)
58  return AVERROR_INVALIDDATA;
59 
60  if (!memcmp(buffer, "end_head", 8)) {
61  if (!st->codec->bits_per_coded_sample)
62  st->codec->bits_per_coded_sample = bps << 3;
63 
64  if (!av_strcasecmp(coding, "pcm")) {
66  0, be, 0xFFFF);
67  } else if (!av_strcasecmp(coding, "alaw")) {
69  } else if (!av_strcasecmp(coding, "ulaw") ||
70  !av_strcasecmp(coding, "mu-law")) {
72  } else {
73  av_log_ask_for_sample(s, "unsupported coding: %s\n", coding);
74  }
75 
76  avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);
77 
79 
80  if (avio_tell(s->pb) > header_size)
81  return AVERROR_INVALIDDATA;
82 
83  avio_skip(s->pb, header_size - avio_tell(s->pb));
84 
85  return 0;
86  } else if (!memcmp(buffer, "channel_count", 13)) {
87  sscanf(buffer, "%*s %*s %"SCNd32, &st->codec->channels);
88  } else if (!memcmp(buffer, "sample_byte_format", 18)) {
89  sscanf(buffer, "%*s %*s %31s", format);
90 
91  if (!av_strcasecmp(format, "01")) {
92  be = 0;
93  } else if (!av_strcasecmp(format, "10")) {
94  be = 1;
95  } else if (av_strcasecmp(format, "1")) {
96  av_log_ask_for_sample(s, "unsupported sample byte format: %s\n", format);
97  return AVERROR_PATCHWELCOME;
98  }
99  } else if (!memcmp(buffer, "sample_coding", 13)) {
100  sscanf(buffer, "%*s %*s %31s", coding);
101  } else if (!memcmp(buffer, "sample_count", 12)) {
102  sscanf(buffer, "%*s %*s %"SCNd64, &st->duration);
103  } else if (!memcmp(buffer, "sample_n_bytes", 14)) {
104  sscanf(buffer, "%*s %*s %"SCNd32, &bps);
105  } else if (!memcmp(buffer, "sample_rate", 11)) {
106  sscanf(buffer, "%*s %*s %"SCNd32, &st->codec->sample_rate);
107  } else if (!memcmp(buffer, "sample_sig_bits", 15)) {
108  sscanf(buffer, "%*s %*s %"SCNd32, &st->codec->bits_per_coded_sample);
109  } else {
110  char key[32], value[32];
111  sscanf(buffer, "%31s %*s %31s", key, value);
112  av_dict_set(&s->metadata, key, value, AV_DICT_APPEND);
113  }
114  }
115 
116  return AVERROR_EOF;
117 }
118 
120  .name = "nistsphere",
121  .long_name = NULL_IF_CONFIG_SMALL("NIST SPeech HEader REsources"),
122  .read_probe = nist_probe,
123  .read_header = nist_read_header,
124  .read_packet = ff_pcm_read_packet,
125  .read_seek = ff_pcm_read_seek,
126  .extensions = "nist,sph",
127  .flags = AVFMT_GENERIC_INDEX,
128 };