FFmpeg coverage

Directory: ../../../ffmpeg/
File: src/libavformat/westwood_aud.c
Date: 2024-11-20 23:03:26
Exec Total Coverage
Lines: 46 71 64.8%
Functions: 3 3 100.0%
Branches: 22 39 56.4%
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1 /*
2 * Westwood Studios AUD Format Demuxer
3 * Copyright (c) 2003 The FFmpeg project
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 /**
23 * @file
24 * Westwood Studios AUD file demuxer
25 * by Mike Melanson (melanson@pcisys.net)
26 * for more information on the Westwood file formats, visit:
27 * http://www.pcisys.net/~melanson/codecs/
28 * http://www.geocities.com/SiliconValley/8682/aud3.txt
29 *
30 * Implementation note: There is no definite file signature for AUD files.
31 * The demuxer uses a probabilistic strategy for content detection. This
32 * entails performing sanity checks on certain header values in order to
33 * qualify a file. Refer to wsaud_probe() for the precise parameters.
34 */
35
36 #include "libavutil/channel_layout.h"
37 #include "libavutil/intreadwrite.h"
38 #include "avformat.h"
39 #include "demux.h"
40 #include "internal.h"
41
42 #define AUD_HEADER_SIZE 12
43 #define AUD_CHUNK_PREAMBLE_SIZE 8
44 #define AUD_CHUNK_SIGNATURE 0x0000DEAF
45
46 7186 static int wsaud_probe(const AVProbeData *p)
47 {
48 int field;
49
50 /* Probabilistic content detection strategy: There is no file signature
51 * so perform sanity checks on various header parameters:
52 * 8000 <= sample rate (16 bits) <= 48000 ==> 40001 acceptable numbers
53 * flags <= 0x03 (2 LSBs are used) ==> 4 acceptable numbers
54 * compression type (8 bits) = 1 or 99 ==> 2 acceptable numbers
55 * first audio chunk signature (32 bits) ==> 1 acceptable number
56 * The number space contains 2^64 numbers. There are 40001 * 4 * 2 * 1 =
57 * 320008 acceptable number combinations.
58 */
59
60
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 7186 if (p->buf_size < AUD_HEADER_SIZE + AUD_CHUNK_PREAMBLE_SIZE)
61 ✗ return 0;
62
63 /* check sample rate */
64 7186 field = AV_RL16(&p->buf[0]);
65
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 7186 if ((field < 8000) || (field > 48000))
66 2082 return 0;
67
68 /* enforce the rule that the top 6 bits of this flags field are reserved (0);
69 * this might not be true, but enforce it until deemed unnecessary */
70
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 5104 if (p->buf[10] & 0xFC)
71 4447 return 0;
72
73
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 657 if (p->buf[11] != 99 && p->buf[11] != 1)
74 639 return 0;
75
76 /* read ahead to the first audio chunk and validate the first header signature */
77
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 18 if (AV_RL32(&p->buf[16]) != AUD_CHUNK_SIGNATURE)
78 16 return 0;
79
80 /* return 1/2 certainty since this file check is a little sketchy */
81 2 return AVPROBE_SCORE_EXTENSION;
82 }
83
84 2 static int wsaud_read_header(AVFormatContext *s)
85 {
86 2 AVIOContext *pb = s->pb;
87 AVStream *st;
88 unsigned char header[AUD_HEADER_SIZE];
89 int sample_rate, channels, codec;
90
91
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 2 if (avio_read(pb, header, AUD_HEADER_SIZE) != AUD_HEADER_SIZE)
92 ✗ return AVERROR(EIO);
93
94 2 sample_rate = AV_RL16(&header[0]);
95 2 channels = (header[10] & 0x1) + 1;
96 2 codec = header[11];
97
98 /* initialize the audio decoder stream */
99 2 st = avformat_new_stream(s, NULL);
100
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 2 if (!st)
101 ✗ return AVERROR(ENOMEM);
102
103
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 2 switch (codec) {
104 ✗ case 1:
105 ✗ if (channels != 1) {
106 ✗ avpriv_request_sample(s, "Stereo WS-SND1");
107 ✗ return AVERROR_PATCHWELCOME;
108 }
109 ✗ st->codecpar->codec_id = AV_CODEC_ID_WESTWOOD_SND1;
110 ✗ break;
111 2 case 99:
112 2 st->codecpar->codec_id = AV_CODEC_ID_ADPCM_IMA_WS;
113 2 st->codecpar->bits_per_coded_sample = 4;
114 2 st->codecpar->bit_rate = channels * sample_rate * 4;
115 2 break;
116 ✗ default:
117 ✗ avpriv_request_sample(s, "Unknown codec: %d", codec);
118 ✗ return AVERROR_PATCHWELCOME;
119 }
120 2 avpriv_set_pts_info(st, 64, 1, sample_rate);
121 2 st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
122 2 av_channel_layout_default(&st->codecpar->ch_layout, channels);
123 2 st->codecpar->sample_rate = sample_rate;
124
125 2 return 0;
126 }
127
128 273 static int wsaud_read_packet(AVFormatContext *s,
129 AVPacket *pkt)
130 {
131 273 AVIOContext *pb = s->pb;
132 unsigned char preamble[AUD_CHUNK_PREAMBLE_SIZE];
133 unsigned int chunk_size;
134 273 int ret = 0;
135 273 AVStream *st = s->streams[0];
136
137
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 273 if (avio_read(pb, preamble, AUD_CHUNK_PREAMBLE_SIZE) !=
138 AUD_CHUNK_PREAMBLE_SIZE)
139 3 return AVERROR(EIO);
140
141 /* validate the chunk */
142
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 270 if (AV_RL32(&preamble[4]) != AUD_CHUNK_SIGNATURE)
143 ✗ return AVERROR_INVALIDDATA;
144
145 270 chunk_size = AV_RL16(&preamble[0]);
146
147
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 270 if (st->codecpar->codec_id == AV_CODEC_ID_WESTWOOD_SND1) {
148 /* For Westwood SND1 audio we need to add the output size and input
149 size to the start of the packet to match what is in VQA.
150 Specifically, this is needed to signal when a packet should be
151 decoding as raw 8-bit pcm or variable-size ADPCM. */
152 ✗ int out_size = AV_RL16(&preamble[2]);
153 ✗ if ((ret = av_new_packet(pkt, chunk_size + 4)) < 0)
154 ✗ return ret;
155 ✗ if ((ret = avio_read(pb, &pkt->data[4], chunk_size)) != chunk_size)
156 ✗ return ret < 0 ? ret : AVERROR(EIO);
157 ✗ AV_WL16(&pkt->data[0], out_size);
158 ✗ AV_WL16(&pkt->data[2], chunk_size);
159
160 ✗ pkt->duration = out_size;
161 } else {
162 270 ret = av_get_packet(pb, pkt, chunk_size);
163
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 270 if (ret != chunk_size)
164 ✗ return AVERROR(EIO);
165
166
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 270 if (st->codecpar->ch_layout.nb_channels <= 0) {
167 ✗ av_log(s, AV_LOG_ERROR, "invalid number of channels %d\n",
168 ✗ st->codecpar->ch_layout.nb_channels);
169 ✗ return AVERROR_INVALIDDATA;
170 }
171
172 /* 2 samples/byte, 1 or 2 samples per frame depending on stereo */
173 270 pkt->duration = (chunk_size * 2) / st->codecpar->ch_layout.nb_channels;
174 }
175 270 pkt->stream_index = st->index;
176
177 270 return ret;
178 }
179
180 const FFInputFormat ff_wsaud_demuxer = {
181 .p.name = "wsaud",
182 .p.long_name = NULL_IF_CONFIG_SMALL("Westwood Studios audio"),
183 .read_probe = wsaud_probe,
184 .read_header = wsaud_read_header,
185 .read_packet = wsaud_read_packet,
186 };
187