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xwma.c
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1 /*
2  * xWMA demuxer
3  * Copyright (c) 2011 Max Horn
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 <inttypes.h>
23 #include <stdint.h>
24 
25 #include "avformat.h"
26 #include "internal.h"
27 #include "riff.h"
28 
29 /*
30  * Demuxer for xWMA, a Microsoft audio container used by XAudio 2.
31  */
32 
33 typedef struct XWMAContext {
34  int64_t data_end;
35 } XWMAContext;
36 
37 static int xwma_probe(AVProbeData *p)
38 {
39  if (!memcmp(p->buf, "RIFF", 4) && !memcmp(p->buf + 8, "XWMA", 4))
40  return AVPROBE_SCORE_MAX;
41  return 0;
42 }
43 
45 {
46  int64_t size;
47  int ret = 0;
48  uint32_t dpds_table_size = 0;
49  uint32_t *dpds_table = NULL;
50  unsigned int tag;
51  AVIOContext *pb = s->pb;
52  AVStream *st;
53  XWMAContext *xwma = s->priv_data;
54  int i;
55 
56  /* The following code is mostly copied from wav.c, with some
57  * minor alterations.
58  */
59 
60  /* check RIFF header */
61  tag = avio_rl32(pb);
62  if (tag != MKTAG('R', 'I', 'F', 'F'))
63  return -1;
64  avio_rl32(pb); /* file size */
65  tag = avio_rl32(pb);
66  if (tag != MKTAG('X', 'W', 'M', 'A'))
67  return -1;
68 
69  /* parse fmt header */
70  tag = avio_rl32(pb);
71  if (tag != MKTAG('f', 'm', 't', ' '))
72  return -1;
73  size = avio_rl32(pb);
74  st = avformat_new_stream(s, NULL);
75  if (!st)
76  return AVERROR(ENOMEM);
77 
78  ret = ff_get_wav_header(s, pb, st->codecpar, size, 0);
79  if (ret < 0)
80  return ret;
82 
83  /* All xWMA files I have seen contained WMAv2 data. If there are files
84  * using WMA Pro or some other codec, then we need to figure out the right
85  * extradata for that. Thus, ask the user for feedback, but try to go on
86  * anyway.
87  */
88  if (st->codecpar->codec_id != AV_CODEC_ID_WMAV2 &&
90  avpriv_request_sample(s, "Unexpected codec (tag %s; id %d)",
92  st->codecpar->codec_id);
93  } else {
94  /* In all xWMA files I have seen, there is no extradata. But the WMA
95  * codecs require extradata, so we provide our own fake extradata.
96  *
97  * First, check that there really was no extradata in the header. If
98  * there was, then try to use it, after asking the user to provide a
99  * sample of this unusual file.
100  */
101  if (st->codecpar->extradata_size != 0) {
102  /* Surprise, surprise: We *did* get some extradata. No idea
103  * if it will work, but just go on and try it, after asking
104  * the user for a sample.
105  */
106  avpriv_request_sample(s, "Unexpected extradata (%d bytes)",
107  st->codecpar->extradata_size);
108  } else if (st->codecpar->codec_id == AV_CODEC_ID_WMAPRO) {
109  if (ff_alloc_extradata(st->codecpar, 18))
110  return AVERROR(ENOMEM);
111 
112  memset(st->codecpar->extradata, 0, st->codecpar->extradata_size);
114  st->codecpar->extradata[14] = 224;
115  } else {
116  if (ff_alloc_extradata(st->codecpar, 6))
117  return AVERROR(ENOMEM);
118 
119  memset(st->codecpar->extradata, 0, st->codecpar->extradata_size);
120  /* setup extradata with our experimentally obtained value */
121  st->codecpar->extradata[4] = 31;
122  }
123  }
124 
125  if (!st->codecpar->channels) {
126  av_log(s, AV_LOG_WARNING, "Invalid channel count: %d\n",
127  st->codecpar->channels);
128  return AVERROR_INVALIDDATA;
129  }
130  if (!st->codecpar->bits_per_coded_sample) {
131  av_log(s, AV_LOG_WARNING, "Invalid bits_per_coded_sample: %d\n",
133  return AVERROR_INVALIDDATA;
134  }
135 
136  /* set the sample rate */
137  avpriv_set_pts_info(st, 64, 1, st->codecpar->sample_rate);
138 
139  /* parse the remaining RIFF chunks */
140  for (;;) {
141  if (pb->eof_reached) {
142  ret = AVERROR_EOF;
143  goto fail;
144  }
145  /* read next chunk tag */
146  tag = avio_rl32(pb);
147  size = avio_rl32(pb);
148  if (tag == MKTAG('d', 'a', 't', 'a')) {
149  /* We assume that the data chunk comes last. */
150  break;
151  } else if (tag == MKTAG('d','p','d','s')) {
152  /* Quoting the MSDN xWMA docs on the dpds chunk: "Contains the
153  * decoded packet cumulative data size array, each element is the
154  * number of bytes accumulated after the corresponding xWMA packet
155  * is decoded in order."
156  *
157  * Each packet has size equal to st->codecpar->block_align, which in
158  * all cases I saw so far was always 2230. Thus, we can use the
159  * dpds data to compute a seeking index.
160  */
161 
162  /* Error out if there is more than one dpds chunk. */
163  if (dpds_table) {
164  av_log(s, AV_LOG_ERROR, "two dpds chunks present\n");
165  ret = AVERROR_INVALIDDATA;
166  goto fail;
167  }
168 
169  /* Compute the number of entries in the dpds chunk. */
170  if (size & 3) { /* Size should be divisible by four */
172  "dpds chunk size %"PRId64" not divisible by 4\n", size);
173  }
174  dpds_table_size = size / 4;
175  if (dpds_table_size == 0 || dpds_table_size >= INT_MAX / 4) {
176  av_log(s, AV_LOG_ERROR,
177  "dpds chunk size %"PRId64" invalid\n", size);
178  return AVERROR_INVALIDDATA;
179  }
180 
181  /* Allocate some temporary storage to keep the dpds data around.
182  * for processing later on.
183  */
184  dpds_table = av_malloc_array(dpds_table_size, sizeof(uint32_t));
185  if (!dpds_table) {
186  return AVERROR(ENOMEM);
187  }
188 
189  for (i = 0; i < dpds_table_size; ++i) {
190  dpds_table[i] = avio_rl32(pb);
191  size -= 4;
192  }
193  }
194  avio_skip(pb, size);
195  }
196 
197  /* Determine overall data length */
198  if (size < 0) {
199  ret = AVERROR_INVALIDDATA;
200  goto fail;
201  }
202  if (!size) {
203  xwma->data_end = INT64_MAX;
204  } else
205  xwma->data_end = avio_tell(pb) + size;
206 
207 
208  if (dpds_table && dpds_table_size) {
209  int64_t cur_pos;
210  const uint32_t bytes_per_sample
211  = (st->codecpar->channels * st->codecpar->bits_per_coded_sample) >> 3;
212 
213  /* Estimate the duration from the total number of output bytes. */
214  const uint64_t total_decoded_bytes = dpds_table[dpds_table_size - 1];
215 
216  if (!bytes_per_sample) {
217  av_log(s, AV_LOG_ERROR,
218  "Invalid bits_per_coded_sample %d for %d channels\n",
220  ret = AVERROR_INVALIDDATA;
221  goto fail;
222  }
223 
224  st->duration = total_decoded_bytes / bytes_per_sample;
225 
226  /* Use the dpds data to build a seek table. We can only do this after
227  * we know the offset to the data chunk, as we need that to determine
228  * the actual offset to each input block.
229  * Note: If we allowed ourselves to assume that the data chunk always
230  * follows immediately after the dpds block, we could of course guess
231  * the data block's start offset already while reading the dpds chunk.
232  * I decided against that, just in case other chunks ever are
233  * discovered.
234  */
235  cur_pos = avio_tell(pb);
236  for (i = 0; i < dpds_table_size; ++i) {
237  /* From the number of output bytes that would accumulate in the
238  * output buffer after decoding the first (i+1) packets, we compute
239  * an offset / timestamp pair.
240  */
242  cur_pos + (i+1) * st->codecpar->block_align, /* pos */
243  dpds_table[i] / bytes_per_sample, /* timestamp */
244  st->codecpar->block_align, /* size */
245  0, /* duration */
247  }
248  } else if (st->codecpar->bit_rate) {
249  /* No dpds chunk was present (or only an empty one), so estimate
250  * the total duration using the average bits per sample and the
251  * total data length.
252  */
253  st->duration = (size<<3) * st->codecpar->sample_rate / st->codecpar->bit_rate;
254  }
255 
256 fail:
257  av_free(dpds_table);
258 
259  return ret;
260 }
261 
263 {
264  int ret, size;
265  int64_t left;
266  AVStream *st;
267  XWMAContext *xwma = s->priv_data;
268 
269  st = s->streams[0];
270 
271  left = xwma->data_end - avio_tell(s->pb);
272  if (left <= 0) {
273  return AVERROR_EOF;
274  }
275 
276  /* read a single block; the default block size is 2230. */
277  size = (st->codecpar->block_align > 1) ? st->codecpar->block_align : 2230;
278  size = FFMIN(size, left);
279 
280  ret = av_get_packet(s->pb, pkt, size);
281  if (ret < 0)
282  return ret;
283 
284  pkt->stream_index = 0;
285  return ret;
286 }
287 
289  .name = "xwma",
290  .long_name = NULL_IF_CONFIG_SMALL("Microsoft xWMA"),
291  .priv_data_size = sizeof(XWMAContext),
295 };
#define NULL
Definition: coverity.c:32
const char * s
Definition: avisynth_c.h:768
Bytestream IO Context.
Definition: avio.h:155
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
int av_add_index_entry(AVStream *st, int64_t pos, int64_t timestamp, int size, int distance, int flags)
Add an index entry into a sorted list.
Definition: utils.c:1979
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:182
void avpriv_set_pts_info(AVStream *s, int pts_wrap_bits, unsigned int pts_num, unsigned int pts_den)
Set the time base and wrapping info for a given stream.
Definition: utils.c:4725
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: avcodec.h:4112
static int xwma_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: xwma.c:262
int64_t avio_skip(AVIOContext *s, int64_t offset)
Skip given number of bytes forward.
Definition: aviobuf.c:318
static AVPacket pkt
Format I/O context.
Definition: avformat.h:1349
void void avpriv_request_sample(void *avc, const char *msg,...) av_printf_format(2
Log a generic warning message about a missing feature.
int64_t data_end
Definition: xwma.c:34
enum AVStreamParseType need_parsing
Definition: avformat.h:1081
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:4355
AVStream ** streams
A list of all streams in the file.
Definition: avformat.h:1417
uint32_t tag
Definition: movenc.c:1456
#define AVERROR_EOF
End of file.
Definition: error.h:55
int av_get_packet(AVIOContext *s, AVPacket *pkt, int size)
Allocate and read the payload of a packet and initialize its fields with default values.
Definition: utils.c:289
ptrdiff_t size
Definition: opengl_enc.c:101
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
Definition: avio.h:527
#define av_log(a,...)
int ff_get_wav_header(AVFormatContext *s, AVIOContext *pb, AVCodecParameters *par, int size, int big_endian)
Definition: riffdec.c:91
int64_t bit_rate
The average bitrate of the encoded data (in bits per second).
Definition: avcodec.h:4141
static int xwma_read_header(AVFormatContext *s)
Definition: xwma.c:44
#define AVINDEX_KEYFRAME
Definition: avformat.h:827
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
AVInputFormat ff_xwma_demuxer
Definition: xwma.c:288
unsigned int avio_rl32(AVIOContext *s)
Definition: aviobuf.c:743
#define AVERROR(e)
Definition: error.h:43
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:179
#define av_fourcc2str(fourcc)
Definition: avutil.h:348
static int xwma_probe(AVProbeData *p)
Definition: xwma.c:37
#define fail()
Definition: checkasm.h:90
int extradata_size
Size of the extradata content in bytes.
Definition: avcodec.h:4130
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:463
int block_align
Audio only.
Definition: avcodec.h:4229
int ff_alloc_extradata(AVCodecParameters *par, int size)
Allocate extradata with additional AV_INPUT_BUFFER_PADDING_SIZE at end which is always set to 0...
Definition: utils.c:3212
#define FFMIN(a, b)
Definition: common.h:96
static int read_probe(AVProbeData *pd)
Definition: jvdec.c:55
internal header for RIFF based (de)muxers do NOT include this in end user applications ...
static int read_header(FFV1Context *f)
Definition: ffv1dec.c:510
Stream structure.
Definition: avformat.h:889
static int read_packet(void *opaque, uint8_t *buf, int buf_size)
Definition: avio_reading.c:42
AVIOContext * pb
I/O context.
Definition: avformat.h:1391
This structure contains the data a format has to probe a file.
Definition: avformat.h:461
int64_t duration
Decoding: duration of the stream, in stream time base.
Definition: avformat.h:946
int sample_rate
Audio only.
Definition: avcodec.h:4222
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:473
Main libavformat public API header.
#define av_free(p)
int eof_reached
true if eof reached
Definition: avio.h:230
void * priv_data
Format private data.
Definition: avformat.h:1377
int bits_per_coded_sample
The number of bits per sample in the codedwords.
Definition: avcodec.h:4154
uint8_t * extradata
Extra binary data needed for initializing the decoder, codec-dependent.
Definition: avcodec.h:4126
int channels
Audio only.
Definition: avcodec.h:4218
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:664
AVCodecParameters * codecpar
Definition: avformat.h:1252
#define av_malloc_array(a, b)
uint32_t codec_tag
Additional information about the codec (corresponds to the AVI FOURCC).
Definition: avcodec.h:4116
int stream_index
Definition: avcodec.h:1670
#define MKTAG(a, b, c, d)
Definition: common.h:342
This structure stores compressed data.
Definition: avcodec.h:1645