handle malloc failures in ff_get_wav_header
[libav.git] / libavformat / xwma.c
1 /*
2 * xWMA demuxer
3 * Copyright (c) 2011 Max Horn
4 *
5 * This file is part of Libav.
6 *
7 * Libav 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 * Libav 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 Libav; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22 #include "avformat.h"
23 #include "riff.h"
24
25 /*
26 * Demuxer for xWMA, a Microsoft audio container used by XAudio 2.
27 */
28
29 typedef struct {
30 int64_t data_end;
31 } XWMAContext;
32
33 static int xwma_probe(AVProbeData *p)
34 {
35 if (!memcmp(p->buf, "RIFF", 4) && !memcmp(p->buf + 8, "XWMA", 4))
36 return AVPROBE_SCORE_MAX;
37 return 0;
38 }
39
40 static int xwma_read_header(AVFormatContext *s, AVFormatParameters *ap)
41 {
42 int64_t size, av_uninit(data_size);
43 int ret;
44 uint32_t dpds_table_size = 0;
45 uint32_t *dpds_table = 0;
46 unsigned int tag;
47 AVIOContext *pb = s->pb;
48 AVStream *st;
49 XWMAContext *xwma = s->priv_data;
50 int i;
51
52 /* The following code is mostly copied from wav.c, with some
53 * minor alterations.
54 */
55
56 /* check RIFF header */
57 tag = avio_rl32(pb);
58 if (tag != MKTAG('R', 'I', 'F', 'F'))
59 return -1;
60 avio_rl32(pb); /* file size */
61 tag = avio_rl32(pb);
62 if (tag != MKTAG('X', 'W', 'M', 'A'))
63 return -1;
64
65 /* parse fmt header */
66 tag = avio_rl32(pb);
67 if (tag != MKTAG('f', 'm', 't', ' '))
68 return -1;
69 size = avio_rl32(pb);
70 st = av_new_stream(s, 0);
71 if (!st)
72 return AVERROR(ENOMEM);
73
74 ret = ff_get_wav_header(pb, st->codec, size);
75 if (ret < 0)
76 return ret;
77 st->need_parsing = AVSTREAM_PARSE_NONE;
78
79 /* All xWMA files I have seen contained WMAv2 data. If there are files
80 * using WMA Pro or some other codec, then we need to figure out the right
81 * extradata for that. Thus, ask the user for feedback, but try to go on
82 * anyway.
83 */
84 if (st->codec->codec_id != CODEC_ID_WMAV2) {
85 av_log(s, AV_LOG_WARNING, "unexpected codec (tag 0x04%x; id %d)\n",
86 st->codec->codec_tag, st->codec->codec_id);
87 av_log_ask_for_sample(s, NULL);
88 } else {
89 /* In all xWMA files I have seen, there is no extradata. But the WMA
90 * codecs require extradata, so we provide our own fake extradata.
91 *
92 * First, check that there really was no extradata in the header. If
93 * there was, then try to use, after asking the the user to provide a
94 * sample of this unusual file.
95 */
96 if (st->codec->extradata_size != 0) {
97 /* Surprise, surprise: We *did* get some extradata. No idea
98 * if it will work, but just go on and try it, after asking
99 * the user for a sample.
100 */
101 av_log(s, AV_LOG_WARNING, "unexpected extradata (%d bytes)\n",
102 st->codec->extradata_size);
103 av_log_ask_for_sample(s, NULL);
104 } else {
105 st->codec->extradata_size = 6;
106 st->codec->extradata = av_mallocz(6 + FF_INPUT_BUFFER_PADDING_SIZE);
107 if (!st->codec->extradata)
108 return AVERROR(ENOMEM);
109
110 /* setup extradata with our experimentally obtained value */
111 st->codec->extradata[4] = 31;
112 }
113 }
114
115 /* set the sample rate */
116 av_set_pts_info(st, 64, 1, st->codec->sample_rate);
117
118 /* parse the remaining RIFF chunks */
119 for (;;) {
120 if (pb->eof_reached)
121 return -1;
122 /* read next chunk tag */
123 tag = avio_rl32(pb);
124 size = avio_rl32(pb);
125 if (tag == MKTAG('d', 'a', 't', 'a')) {
126 /* We assume that the data chunk comes last. */
127 break;
128 } else if (tag == MKTAG('d','p','d','s')) {
129 /* Quoting the MSDN xWMA docs on the dpds chunk: "Contains the
130 * decoded packet cumulative data size array, each element is the
131 * number of bytes accumulated after the corresponding xWMA packet
132 * is decoded in order"
133 *
134 * Each packet has size equal to st->codec->block_align, which in
135 * all cases I saw so far was always 2230. Thus, we can use the
136 * dpds data to compute a seeking index.
137 */
138
139 /* Error out if there is more than one dpds chunk. */
140 if (dpds_table) {
141 av_log(s, AV_LOG_ERROR, "two dpds chunks present\n");
142 return -1;
143 }
144
145 /* Compute the number of entries in the dpds chunk. */
146 if (size & 3) { /* Size should be divisible by four */
147 av_log(s, AV_LOG_WARNING, "dpds chunk size "PRId64" not divisible by 4\n", size);
148 }
149 dpds_table_size = size / 4;
150 if (dpds_table_size == 0 || dpds_table_size >= INT_MAX / 4) {
151 av_log(s, AV_LOG_ERROR, "dpds chunk size "PRId64" invalid\n", size);
152 return -1;
153 }
154
155 /* Allocate some temporary storage to keep the dpds data around.
156 * for processing later on.
157 */
158 dpds_table = av_malloc(dpds_table_size * sizeof(uint32_t));
159 if (!dpds_table) {
160 return AVERROR(ENOMEM);
161 }
162
163 for (i = 0; i < dpds_table_size; ++i) {
164 dpds_table[i] = avio_rl32(pb);
165 size -= 4;
166 }
167 }
168 avio_skip(pb, size);
169 }
170
171 /* Determine overall data length */
172 if (size < 0)
173 return -1;
174 if (!size) {
175 xwma->data_end = INT64_MAX;
176 } else
177 xwma->data_end = avio_tell(pb) + size;
178
179
180 if (dpds_table && dpds_table_size) {
181 int64_t cur_pos;
182 const uint32_t bytes_per_sample
183 = (st->codec->channels * st->codec->bits_per_coded_sample) >> 3;
184
185 /* Estimate the duration from the total number of output bytes. */
186 const uint64_t total_decoded_bytes = dpds_table[dpds_table_size - 1];
187 st->duration = total_decoded_bytes / bytes_per_sample;
188
189 /* Use the dpds data to build a seek table. We can only do this after
190 * we know the offset to the data chunk, as we need that to determine
191 * the actual offset to each input block.
192 * Note: If we allowed ourselves to assume that the data chunk always
193 * follows immediately after the dpds block, we could of course guess
194 * the data block's start offset already while reading the dpds chunk.
195 * I decided against that, just in case other chunks ever are
196 * discovered.
197 */
198 cur_pos = avio_tell(pb);
199 for (i = 0; i < dpds_table_size; ++i) {
200 /* From the number of output bytes that would accumulate in the
201 * output buffer after decoding the first (i+1) packets, we compute
202 * an offset / timestamp pair.
203 */
204 av_add_index_entry(st,
205 cur_pos + (i+1) * st->codec->block_align, /* pos */
206 dpds_table[i] / bytes_per_sample, /* timestamp */
207 st->codec->block_align, /* size */
208 0, /* duration */
209 AVINDEX_KEYFRAME);
210 }
211 } else if (st->codec->bit_rate) {
212 /* No dpds chunk was present (or only an empty one), so estimate
213 * the total duration using the average bits per sample and the
214 * total data length.
215 */
216 st->duration = (size<<3) * st->codec->sample_rate / st->codec->bit_rate;
217 }
218
219 av_free(dpds_table);
220
221 return 0;
222 }
223
224 static int xwma_read_packet(AVFormatContext *s, AVPacket *pkt)
225 {
226 int ret, size;
227 int64_t left;
228 AVStream *st;
229 XWMAContext *xwma = s->priv_data;
230
231 st = s->streams[0];
232
233 left = xwma->data_end - avio_tell(s->pb);
234 if (left <= 0) {
235 return AVERROR_EOF;
236 }
237
238 /* read a single block; the default block size is 2230. */
239 size = (st->codec->block_align > 1) ? st->codec->block_align : 2230;
240 size = FFMIN(size, left);
241
242 ret = av_get_packet(s->pb, pkt, size);
243 if (ret < 0)
244 return ret;
245
246 pkt->stream_index = 0;
247 return ret;
248 }
249
250 AVInputFormat ff_xwma_demuxer = {
251 "xwma",
252 NULL_IF_CONFIG_SMALL("Microsoft xWMA"),
253 sizeof(XWMAContext),
254 xwma_probe,
255 xwma_read_header,
256 xwma_read_packet,
257 };