Statistics
| Branch: | Revision:

ffmpeg / libavformat / wav.c @ 048446bf

History | View | Annotate | Download (9.52 KB)

1
/* 
2
 * WAV encoder and decoder
3
 * Copyright (c) 2001, 2002 Fabrice Bellard.
4
 *
5
 * This library is free software; you can redistribute it and/or
6
 * modify it under the terms of the GNU Lesser General Public
7
 * License as published by the Free Software Foundation; either
8
 * version 2 of the License, or (at your option) any later version.
9
 *
10
 * This library is distributed in the hope that it will be useful,
11
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13
 * Lesser General Public License for more details.
14
 *
15
 * You should have received a copy of the GNU Lesser General Public
16
 * License along with this library; if not, write to the Free Software
17
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
18
 */
19
#include "avformat.h"
20
#include "avi.h"
21

    
22
const CodecTag codec_wav_tags[] = {
23
    { CODEC_ID_MP2, 0x50 },
24
    { CODEC_ID_MP3LAME, 0x55 },
25
    { CODEC_ID_AC3, 0x2000 },
26
    { CODEC_ID_PCM_S16LE, 0x01 },
27
    { CODEC_ID_PCM_U8, 0x01 }, /* must come after s16le in this list */
28
    { CODEC_ID_PCM_ALAW, 0x06 },
29
    { CODEC_ID_PCM_MULAW, 0x07 },
30
    { CODEC_ID_ADPCM_MS, 0x02 },
31
    { CODEC_ID_ADPCM_IMA_WAV, 0x11 },
32
    { CODEC_ID_ADPCM_IMA_DK4, 0x61 },  /* rogue format number */
33
    { CODEC_ID_ADPCM_IMA_DK3, 0x62 },  /* rogue format number */
34
    { CODEC_ID_WMAV1, 0x160 },
35
    { CODEC_ID_WMAV2, 0x161 },
36
    { 0, 0 },
37
};
38

    
39
/* WAVEFORMATEX header */
40
/* returns the size or -1 on error */
41
int put_wav_header(ByteIOContext *pb, AVCodecContext *enc)
42
{
43
    int bps, blkalign, bytespersec;
44
    int hdrsize = 18;
45

    
46
    if(!enc->codec_tag)
47
       enc->codec_tag = codec_get_tag(codec_wav_tags, enc->codec_id);
48
    if(!enc->codec_tag)
49
        return -1;
50

    
51
    put_le16(pb, enc->codec_tag);
52
    put_le16(pb, enc->channels);
53
    put_le32(pb, enc->sample_rate);
54
    if (enc->codec_id == CODEC_ID_PCM_U8 ||
55
        enc->codec_id == CODEC_ID_PCM_ALAW ||
56
        enc->codec_id == CODEC_ID_PCM_MULAW) {
57
        bps = 8;
58
    } else if (enc->codec_id == CODEC_ID_MP2 || enc->codec_id == CODEC_ID_MP3LAME) {
59
        bps = 0;
60
    } else if (enc->codec_id == CODEC_ID_ADPCM_IMA_WAV || enc->codec_id == CODEC_ID_ADPCM_MS) {
61
        bps = 4;
62
    } else {
63
        bps = 16;
64
    }
65
    
66
    if (enc->codec_id == CODEC_ID_MP2 || enc->codec_id == CODEC_ID_MP3LAME) {
67
        blkalign = 1;
68
        //blkalign = 144 * enc->bit_rate/enc->sample_rate;
69
    } else if (enc->block_align != 0) { /* specified by the codec */
70
        blkalign = enc->block_align;
71
    } else
72
        blkalign = enc->channels*bps >> 3;
73
    if (enc->codec_id == CODEC_ID_PCM_U8 ||
74
        enc->codec_id == CODEC_ID_PCM_S16LE) {
75
        bytespersec = enc->sample_rate * blkalign;
76
    } else {
77
        bytespersec = enc->bit_rate / 8;
78
    }
79
    put_le32(pb, bytespersec); /* bytes per second */
80
    put_le16(pb, blkalign); /* block align */
81
    put_le16(pb, bps); /* bits per sample */
82
    if (enc->codec_id == CODEC_ID_MP3LAME) {
83
        put_le16(pb, 12); /* wav_extra_size */
84
        hdrsize += 12;
85
        put_le16(pb, 1); /* wID */
86
        put_le32(pb, 2); /* fdwFlags */
87
        put_le16(pb, 1152); /* nBlockSize */
88
        put_le16(pb, 1); /* nFramesPerBlock */
89
        put_le16(pb, 1393); /* nCodecDelay */
90
    } else if (enc->codec_id == CODEC_ID_MP2) {
91
        put_le16(pb, 22); /* wav_extra_size */
92
        hdrsize += 22;
93
        put_le16(pb, 2);  /* fwHeadLayer */
94
        put_le32(pb, enc->bit_rate); /* dwHeadBitrate */
95
        put_le16(pb, enc->channels == 2 ? 1 : 8); /* fwHeadMode */
96
        put_le16(pb, 0);  /* fwHeadModeExt */
97
        put_le16(pb, 1);  /* wHeadEmphasis */
98
        put_le16(pb, 16); /* fwHeadFlags */
99
        put_le32(pb, 0);  /* dwPTSLow */
100
        put_le32(pb, 0);  /* dwPTSHigh */
101
    } else if (enc->codec_id == CODEC_ID_ADPCM_IMA_WAV) {
102
        put_le16(pb, 2); /* wav_extra_size */
103
        put_le16(pb, ((enc->block_align - 4 * enc->channels) / (4 * enc->channels)) * 8 + 1); /* wSamplesPerBlock */
104
    } else
105
        put_le16(pb, 0); /* wav_extra_size */
106

    
107
    return hdrsize;
108
}
109

    
110
/* We could be given one of the three possible structures here:
111
 * WAVEFORMAT, PCMWAVEFORMAT or WAVEFORMATEX. Each structure
112
 * is an expansion of the previous one with the fields added
113
 * at the bottom. PCMWAVEFORMAT adds 'WORD wBitsPerSample' and
114
 * WAVEFORMATEX adds 'WORD  cbSize' and basically makes itself
115
 * an openended structure.
116
 */
117
void get_wav_header(ByteIOContext *pb, AVCodecContext *codec, int size) 
118
{
119
    int id;
120

    
121
    id = get_le16(pb);
122
    codec->codec_type = CODEC_TYPE_AUDIO;
123
    codec->codec_tag = id;
124
    codec->channels = get_le16(pb);
125
    codec->sample_rate = get_le32(pb);
126
    codec->bit_rate = get_le32(pb) * 8;
127
    codec->block_align = get_le16(pb);
128
    if (size == 14) {  /* We're dealing with plain vanilla WAVEFORMAT */
129
        codec->bits_per_sample = 8;
130
    }else
131
        codec->bits_per_sample = get_le16(pb);
132
    codec->codec_id = wav_codec_get_id(id, codec->bits_per_sample);
133

    
134
    if (size > 16) {  /* We're obviously dealing with WAVEFORMATEX */
135
        codec->extradata_size = get_le16(pb);
136
        if (codec->extradata_size > 0) {
137
            if (codec->extradata_size > size - 18)
138
                codec->extradata_size = size - 18;
139
            codec->extradata = av_mallocz(codec->extradata_size);
140
            get_buffer(pb, codec->extradata, codec->extradata_size);
141
        } else
142
            codec->extradata_size = 0;
143
        
144
        /* It is possible for the chunk to contain garbage at the end */
145
        if (size - codec->extradata_size - 18 > 0)
146
            url_fskip(pb, size - codec->extradata_size - 18);
147
    }
148
}
149

    
150

    
151
int wav_codec_get_id(unsigned int tag, int bps)
152
{
153
    int id;
154
    id = codec_get_id(codec_wav_tags, tag);
155
    if (id <= 0)
156
        return id;
157
    /* handle specific u8 codec */
158
    if (id == CODEC_ID_PCM_S16LE && bps == 8)
159
        id = CODEC_ID_PCM_U8;
160
    return id;
161
}
162

    
163
typedef struct {
164
    offset_t data;
165
} WAVContext;
166

    
167
static int wav_write_header(AVFormatContext *s)
168
{
169
    WAVContext *wav = s->priv_data;
170
    ByteIOContext *pb = &s->pb;
171
    offset_t fmt;
172

    
173
    put_tag(pb, "RIFF");
174
    put_le32(pb, 0); /* file length */
175
    put_tag(pb, "WAVE");
176

    
177
    /* format header */
178
    fmt = start_tag(pb, "fmt ");
179
    if (put_wav_header(pb, &s->streams[0]->codec) < 0) {
180
        av_free(wav);
181
        return -1;
182
    }
183
    end_tag(pb, fmt);
184

    
185
    /* data header */
186
    wav->data = start_tag(pb, "data");
187
    
188
    put_flush_packet(pb);
189

    
190
    return 0;
191
}
192

    
193
static int wav_write_packet(AVFormatContext *s, int stream_index_ptr,
194
                           uint8_t *buf, int size, int force_pts)
195
{
196
    ByteIOContext *pb = &s->pb;
197
    put_buffer(pb, buf, size);
198
    return 0;
199
}
200

    
201
static int wav_write_trailer(AVFormatContext *s)
202
{
203
    ByteIOContext *pb = &s->pb;
204
    WAVContext *wav = s->priv_data;
205
    offset_t file_size;
206

    
207
    if (!url_is_streamed(&s->pb)) {
208
        end_tag(pb, wav->data);
209

    
210
        /* update file size */
211
        file_size = url_ftell(pb);
212
        url_fseek(pb, 4, SEEK_SET);
213
        put_le32(pb, (uint32_t)(file_size - 8));
214
        url_fseek(pb, file_size, SEEK_SET);
215

    
216
        put_flush_packet(pb);
217
    }
218
    return 0;
219
}
220

    
221
/* return the size of the found tag */
222
/* XXX: > 2GB ? */
223
static int find_tag(ByteIOContext *pb, uint32_t tag1)
224
{
225
    unsigned int tag;
226
    int size;
227

    
228
    for(;;) {
229
        if (url_feof(pb))
230
            return -1;
231
        tag = get_le32(pb);
232
        size = get_le32(pb);
233
        if (tag == tag1)
234
            break;
235
        url_fseek(pb, size, SEEK_CUR);
236
    }
237
    if (size < 0)
238
        size = 0x7fffffff;
239
    return size;
240
}
241

    
242
static int wav_probe(AVProbeData *p)
243
{
244
    /* check file header */
245
    if (p->buf_size <= 32)
246
        return 0;
247
    if (p->buf[0] == 'R' && p->buf[1] == 'I' &&
248
        p->buf[2] == 'F' && p->buf[3] == 'F' &&
249
        p->buf[8] == 'W' && p->buf[9] == 'A' &&
250
        p->buf[10] == 'V' && p->buf[11] == 'E')
251
        return AVPROBE_SCORE_MAX;
252
    else
253
        return 0;
254
}
255

    
256
/* wav input */
257
static int wav_read_header(AVFormatContext *s,
258
                           AVFormatParameters *ap)
259
{
260
    int size;
261
    unsigned int tag;
262
    ByteIOContext *pb = &s->pb;
263
    AVStream *st;
264

    
265
    /* check RIFF header */
266
    tag = get_le32(pb);
267

    
268
    if (tag != MKTAG('R', 'I', 'F', 'F'))
269
        return -1;
270
    get_le32(pb); /* file size */
271
    tag = get_le32(pb);
272
    if (tag != MKTAG('W', 'A', 'V', 'E'))
273
        return -1;
274
    
275
    /* parse fmt header */
276
    size = find_tag(pb, MKTAG('f', 'm', 't', ' '));
277
    if (size < 0)
278
        return -1;
279
    st = av_new_stream(s, 0);
280
    if (!st)
281
        return AVERROR_NOMEM;
282

    
283
    get_wav_header(pb, &st->codec, size);
284
    
285
    size = find_tag(pb, MKTAG('d', 'a', 't', 'a'));
286
    if (size < 0)
287
        return -1;
288
    return 0;
289
}
290

    
291
#define MAX_SIZE 4096
292

    
293
static int wav_read_packet(AVFormatContext *s,
294
                           AVPacket *pkt)
295
{
296
    int ret;
297

    
298
    if (url_feof(&s->pb))
299
        return -EIO;
300
    if (av_new_packet(pkt, MAX_SIZE))
301
        return -EIO;
302
    pkt->stream_index = 0;
303

    
304
    ret = get_buffer(&s->pb, pkt->data, pkt->size);
305
    if (ret < 0)
306
        av_free_packet(pkt);
307
    /* note: we need to modify the packet size here to handle the last
308
       packet */
309
    pkt->size = ret;
310
    return ret;
311
}
312

    
313
static int wav_read_close(AVFormatContext *s)
314
{
315
    return 0;
316
}
317

    
318
static AVInputFormat wav_iformat = {
319
    "wav",
320
    "wav format",
321
    0,
322
    wav_probe,
323
    wav_read_header,
324
    wav_read_packet,
325
    wav_read_close,
326
};
327

    
328
static AVOutputFormat wav_oformat = {
329
    "wav",
330
    "wav format",
331
    "audio/x-wav",
332
    "wav",
333
    sizeof(WAVContext),
334
    CODEC_ID_PCM_S16LE,
335
    CODEC_ID_NONE,
336
    wav_write_header,
337
    wav_write_packet,
338
    wav_write_trailer,
339
};
340

    
341
int wav_init(void)
342
{
343
    av_register_input_format(&wav_iformat);
344
    av_register_output_format(&wav_oformat);
345
    return 0;
346
}