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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 0x04%x; id %d)",
91  st->codecpar->codec_tag, st->codecpar->codec_id);
92  } else {
93  /* In all xWMA files I have seen, there is no extradata. But the WMA
94  * codecs require extradata, so we provide our own fake extradata.
95  *
96  * First, check that there really was no extradata in the header. If
97  * there was, then try to use it, after asking the user to provide a
98  * sample of this unusual file.
99  */
100  if (st->codecpar->extradata_size != 0) {
101  /* Surprise, surprise: We *did* get some extradata. No idea
102  * if it will work, but just go on and try it, after asking
103  * the user for a sample.
104  */
105  avpriv_request_sample(s, "Unexpected extradata (%d bytes)",
106  st->codecpar->extradata_size);
107  } else if (st->codecpar->codec_id == AV_CODEC_ID_WMAPRO) {
108  if (ff_alloc_extradata(st->codecpar, 18))
109  return AVERROR(ENOMEM);
110 
111  memset(st->codecpar->extradata, 0, st->codecpar->extradata_size);
113  st->codecpar->extradata[14] = 224;
114  } else {
115  if (ff_alloc_extradata(st->codecpar, 6))
116  return AVERROR(ENOMEM);
117 
118  memset(st->codecpar->extradata, 0, st->codecpar->extradata_size);
119  /* setup extradata with our experimentally obtained value */
120  st->codecpar->extradata[4] = 31;
121  }
122  }
123 
124  if (!st->codecpar->channels) {
125  av_log(s, AV_LOG_WARNING, "Invalid channel count: %d\n",
126  st->codecpar->channels);
127  return AVERROR_INVALIDDATA;
128  }
129  if (!st->codecpar->bits_per_coded_sample) {
130  av_log(s, AV_LOG_WARNING, "Invalid bits_per_coded_sample: %d\n",
132  return AVERROR_INVALIDDATA;
133  }
134 
135  /* set the sample rate */
136  avpriv_set_pts_info(st, 64, 1, st->codecpar->sample_rate);
137 
138  /* parse the remaining RIFF chunks */
139  for (;;) {
140  if (pb->eof_reached) {
141  ret = AVERROR_EOF;
142  goto fail;
143  }
144  /* read next chunk tag */
145  tag = avio_rl32(pb);
146  size = avio_rl32(pb);
147  if (tag == MKTAG('d', 'a', 't', 'a')) {
148  /* We assume that the data chunk comes last. */
149  break;
150  } else if (tag == MKTAG('d','p','d','s')) {
151  /* Quoting the MSDN xWMA docs on the dpds chunk: "Contains the
152  * decoded packet cumulative data size array, each element is the
153  * number of bytes accumulated after the corresponding xWMA packet
154  * is decoded in order."
155  *
156  * Each packet has size equal to st->codecpar->block_align, which in
157  * all cases I saw so far was always 2230. Thus, we can use the
158  * dpds data to compute a seeking index.
159  */
160 
161  /* Error out if there is more than one dpds chunk. */
162  if (dpds_table) {
163  av_log(s, AV_LOG_ERROR, "two dpds chunks present\n");
164  ret = AVERROR_INVALIDDATA;
165  goto fail;
166  }
167 
168  /* Compute the number of entries in the dpds chunk. */
169  if (size & 3) { /* Size should be divisible by four */
171  "dpds chunk size %"PRId64" not divisible by 4\n", size);
172  }
173  dpds_table_size = size / 4;
174  if (dpds_table_size == 0 || dpds_table_size >= INT_MAX / 4) {
175  av_log(s, AV_LOG_ERROR,
176  "dpds chunk size %"PRId64" invalid\n", size);
177  return AVERROR_INVALIDDATA;
178  }
179 
180  /* Allocate some temporary storage to keep the dpds data around.
181  * for processing later on.
182  */
183  dpds_table = av_malloc_array(dpds_table_size, sizeof(uint32_t));
184  if (!dpds_table) {
185  return AVERROR(ENOMEM);
186  }
187 
188  for (i = 0; i < dpds_table_size; ++i) {
189  dpds_table[i] = avio_rl32(pb);
190  size -= 4;
191  }
192  }
193  avio_skip(pb, size);
194  }
195 
196  /* Determine overall data length */
197  if (size < 0) {
198  ret = AVERROR_INVALIDDATA;
199  goto fail;
200  }
201  if (!size) {
202  xwma->data_end = INT64_MAX;
203  } else
204  xwma->data_end = avio_tell(pb) + size;
205 
206 
207  if (dpds_table && dpds_table_size) {
208  int64_t cur_pos;
209  const uint32_t bytes_per_sample
210  = (st->codecpar->channels * st->codecpar->bits_per_coded_sample) >> 3;
211 
212  /* Estimate the duration from the total number of output bytes. */
213  const uint64_t total_decoded_bytes = dpds_table[dpds_table_size - 1];
214 
215  if (!bytes_per_sample) {
216  av_log(s, AV_LOG_ERROR,
217  "Invalid bits_per_coded_sample %d for %d channels\n",
219  ret = AVERROR_INVALIDDATA;
220  goto fail;
221  }
222 
223  st->duration = total_decoded_bytes / bytes_per_sample;
224 
225  /* Use the dpds data to build a seek table. We can only do this after
226  * we know the offset to the data chunk, as we need that to determine
227  * the actual offset to each input block.
228  * Note: If we allowed ourselves to assume that the data chunk always
229  * follows immediately after the dpds block, we could of course guess
230  * the data block's start offset already while reading the dpds chunk.
231  * I decided against that, just in case other chunks ever are
232  * discovered.
233  */
234  cur_pos = avio_tell(pb);
235  for (i = 0; i < dpds_table_size; ++i) {
236  /* From the number of output bytes that would accumulate in the
237  * output buffer after decoding the first (i+1) packets, we compute
238  * an offset / timestamp pair.
239  */
241  cur_pos + (i+1) * st->codecpar->block_align, /* pos */
242  dpds_table[i] / bytes_per_sample, /* timestamp */
243  st->codecpar->block_align, /* size */
244  0, /* duration */
246  }
247  } else if (st->codecpar->bit_rate) {
248  /* No dpds chunk was present (or only an empty one), so estimate
249  * the total duration using the average bits per sample and the
250  * total data length.
251  */
252  st->duration = (size<<3) * st->codecpar->sample_rate / st->codecpar->bit_rate;
253  }
254 
255 fail:
256  av_free(dpds_table);
257 
258  return ret;
259 }
260 
262 {
263  int ret, size;
264  int64_t left;
265  AVStream *st;
266  XWMAContext *xwma = s->priv_data;
267 
268  st = s->streams[0];
269 
270  left = xwma->data_end - avio_tell(s->pb);
271  if (left <= 0) {
272  return AVERROR_EOF;
273  }
274 
275  /* read a single block; the default block size is 2230. */
276  size = (st->codecpar->block_align > 1) ? st->codecpar->block_align : 2230;
277  size = FFMIN(size, left);
278 
279  ret = av_get_packet(s->pb, pkt, size);
280  if (ret < 0)
281  return ret;
282 
283  pkt->stream_index = 0;
284  return ret;
285 }
286 
288  .name = "xwma",
289  .long_name = NULL_IF_CONFIG_SMALL("Microsoft xWMA"),
290  .priv_data_size = sizeof(XWMAContext),
294 };
#define NULL
Definition: coverity.c:32
const char * s
Definition: avisynth_c.h:631
Bytestream IO Context.
Definition: avio.h:111
#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:1897
#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:4399
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: avcodec.h:3911
static int xwma_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: xwma.c:261
int64_t avio_skip(AVIOContext *s, int64_t offset)
Skip given number of bytes forward.
Definition: aviobuf.c:287
static AVPacket pkt
Format I/O context.
Definition: avformat.h:1319
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:1074
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:4037
AVStream ** streams
A list of all streams in the file.
Definition: avformat.h:1387
uint32_t tag
Definition: movenc.c:1353
#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:260
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:447
#define av_log(a,...)
int ff_get_wav_header(AVFormatContext *s, AVIOContext *pb, AVCodecParameters *par, int size, int big_endian)
Definition: riffdec.c:88
int64_t bit_rate
The average bitrate of the encoded data (in bits per second).
Definition: avcodec.h:3940
static int xwma_read_header(AVFormatContext *s)
Definition: xwma.c:44
#define AVINDEX_KEYFRAME
Definition: avformat.h:823
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
AVInputFormat ff_xwma_demuxer
Definition: xwma.c:287
unsigned int avio_rl32(AVIOContext *s)
Definition: aviobuf.c:672
#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:176
static int xwma_probe(AVProbeData *p)
Definition: xwma.c:37
#define fail()
Definition: checkasm.h:81
int extradata_size
Size of the extradata content in bytes.
Definition: avcodec.h:3929
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:461
int block_align
Audio only.
Definition: avcodec.h:4028
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:3099
#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:638
Stream structure.
Definition: avformat.h:876
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:1361
This structure contains the data a format has to probe a file.
Definition: avformat.h:459
int64_t duration
Decoding: duration of the stream, in stream time base.
Definition: avformat.h:930
int sample_rate
Audio only.
Definition: avcodec.h:4021
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:471
Main libavformat public API header.
#define av_free(p)
int eof_reached
true if eof reached
Definition: avio.h:186
void * priv_data
Format private data.
Definition: avformat.h:1347
int bits_per_coded_sample
The number of bits per sample in the codedwords.
Definition: avcodec.h:3953
uint8_t * extradata
Extra binary data needed for initializing the decoder, codec-dependent.
Definition: avcodec.h:3925
int channels
Audio only.
Definition: avcodec.h:4017
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:660
AVCodecParameters * codecpar
Definition: avformat.h:1006
#define av_malloc_array(a, b)
uint32_t codec_tag
Additional information about the codec (corresponds to the AVI FOURCC).
Definition: avcodec.h:3915
int stream_index
Definition: avcodec.h:1576
#define MKTAG(a, b, c, d)
Definition: common.h:342
This structure stores compressed data.
Definition: avcodec.h:1551