smacker: return meaningful error codes on failure
[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 <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
44 static int xwma_read_header(AVFormatContext *s)
45 {
46 int64_t size;
47 int ret = 0;
48 uint32_t dpds_table_size = 0;
49 uint32_t *dpds_table = 0;
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);
79 if (ret < 0)
80 return ret;
81 st->need_parsing = AVSTREAM_PARSE_NONE;
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) {
89 avpriv_request_sample(s, "Unexpected codec (tag 0x04%"PRIx32"; id %d)",
90 st->codecpar->codec_tag, st->codecpar->codec_id);
91 } else {
92 /* In all xWMA files I have seen, there is no extradata. But the WMA
93 * codecs require extradata, so we provide our own fake extradata.
94 *
95 * First, check that there really was no extradata in the header. If
96 * there was, then try to use it, after asking the user to provide a
97 * sample of this unusual file.
98 */
99 if (st->codecpar->extradata_size != 0) {
100 /* Surprise, surprise: We *did* get some extradata. No idea
101 * if it will work, but just go on and try it, after asking
102 * the user for a sample.
103 */
104 avpriv_request_sample(s, "Unexpected extradata (%d bytes)",
105 st->codecpar->extradata_size);
106 } else {
107 st->codecpar->extradata_size = 6;
108 st->codecpar->extradata = av_mallocz(6 + AV_INPUT_BUFFER_PADDING_SIZE);
109 if (!st->codecpar->extradata)
110 return AVERROR(ENOMEM);
111
112 /* setup extradata with our experimentally obtained value */
113 st->codecpar->extradata[4] = 31;
114 }
115 }
116
117 if (!st->codecpar->channels) {
118 av_log(s, AV_LOG_WARNING, "Invalid channel count: %d\n",
119 st->codecpar->channels);
120 return AVERROR_INVALIDDATA;
121 }
122 if (!st->codecpar->bits_per_coded_sample) {
123 av_log(s, AV_LOG_WARNING, "Invalid bits_per_coded_sample: %d\n",
124 st->codecpar->bits_per_coded_sample);
125 return AVERROR_INVALIDDATA;
126 }
127
128 /* set the sample rate */
129 avpriv_set_pts_info(st, 64, 1, st->codecpar->sample_rate);
130
131 /* parse the remaining RIFF chunks */
132 for (;;) {
133 if (pb->eof_reached) {
134 ret = AVERROR_INVALIDDATA;
135 goto fail;
136 }
137 /* read next chunk tag */
138 tag = avio_rl32(pb);
139 size = avio_rl32(pb);
140 if (tag == MKTAG('d', 'a', 't', 'a')) {
141 /* We assume that the data chunk comes last. */
142 break;
143 } else if (tag == MKTAG('d','p','d','s')) {
144 /* Quoting the MSDN xWMA docs on the dpds chunk: "Contains the
145 * decoded packet cumulative data size array, each element is the
146 * number of bytes accumulated after the corresponding xWMA packet
147 * is decoded in order."
148 *
149 * Each packet has size equal to st->codecpar->block_align, which in
150 * all cases I saw so far was always 2230. Thus, we can use the
151 * dpds data to compute a seeking index.
152 */
153
154 /* Error out if there is more than one dpds chunk. */
155 if (dpds_table) {
156 av_log(s, AV_LOG_ERROR, "two dpds chunks present\n");
157 ret = AVERROR_INVALIDDATA;
158 goto fail;
159 }
160
161 /* Compute the number of entries in the dpds chunk. */
162 if (size & 3) { /* Size should be divisible by four */
163 av_log(s, AV_LOG_WARNING,
164 "dpds chunk size %"PRId64" not divisible by 4\n", size);
165 }
166 dpds_table_size = size / 4;
167 if (dpds_table_size == 0 || dpds_table_size >= INT_MAX / 4) {
168 av_log(s, AV_LOG_ERROR,
169 "dpds chunk size %"PRId64" invalid\n", size);
170 return -1;
171 }
172
173 /* Allocate some temporary storage to keep the dpds data around.
174 * for processing later on.
175 */
176 dpds_table = av_malloc(dpds_table_size * sizeof(uint32_t));
177 if (!dpds_table) {
178 return AVERROR(ENOMEM);
179 }
180
181 for (i = 0; i < dpds_table_size; ++i) {
182 dpds_table[i] = avio_rl32(pb);
183 size -= 4;
184 }
185 }
186 avio_skip(pb, size);
187 }
188
189 /* Determine overall data length */
190 if (size < 0) {
191 ret = AVERROR_INVALIDDATA;
192 goto fail;
193 }
194 if (!size) {
195 xwma->data_end = INT64_MAX;
196 } else
197 xwma->data_end = avio_tell(pb) + size;
198
199
200 if (dpds_table && dpds_table_size) {
201 int64_t cur_pos;
202 const uint32_t bytes_per_sample
203 = (st->codecpar->channels * st->codecpar->bits_per_coded_sample) >> 3;
204
205 /* Estimate the duration from the total number of output bytes. */
206 const uint64_t total_decoded_bytes = dpds_table[dpds_table_size - 1];
207
208 if (!bytes_per_sample) {
209 av_log(s, AV_LOG_ERROR,
210 "Invalid bits_per_coded_sample %d for %d channels\n",
211 st->codecpar->bits_per_coded_sample, st->codecpar->channels);
212 ret = AVERROR_INVALIDDATA;
213 goto fail;
214 }
215
216 st->duration = total_decoded_bytes / bytes_per_sample;
217
218 /* Use the dpds data to build a seek table. We can only do this after
219 * we know the offset to the data chunk, as we need that to determine
220 * the actual offset to each input block.
221 * Note: If we allowed ourselves to assume that the data chunk always
222 * follows immediately after the dpds block, we could of course guess
223 * the data block's start offset already while reading the dpds chunk.
224 * I decided against that, just in case other chunks ever are
225 * discovered.
226 */
227 cur_pos = avio_tell(pb);
228 for (i = 0; i < dpds_table_size; ++i) {
229 /* From the number of output bytes that would accumulate in the
230 * output buffer after decoding the first (i+1) packets, we compute
231 * an offset / timestamp pair.
232 */
233 av_add_index_entry(st,
234 cur_pos + (i+1) * st->codecpar->block_align, /* pos */
235 dpds_table[i] / bytes_per_sample, /* timestamp */
236 st->codecpar->block_align, /* size */
237 0, /* duration */
238 AVINDEX_KEYFRAME);
239 }
240 } else if (st->codecpar->bit_rate) {
241 /* No dpds chunk was present (or only an empty one), so estimate
242 * the total duration using the average bits per sample and the
243 * total data length.
244 */
245 st->duration = (size<<3) * st->codecpar->sample_rate / st->codecpar->bit_rate;
246 }
247
248 fail:
249 av_free(dpds_table);
250
251 return ret;
252 }
253
254 static int xwma_read_packet(AVFormatContext *s, AVPacket *pkt)
255 {
256 int ret, size;
257 int64_t left;
258 AVStream *st;
259 XWMAContext *xwma = s->priv_data;
260
261 st = s->streams[0];
262
263 left = xwma->data_end - avio_tell(s->pb);
264 if (left <= 0) {
265 return AVERROR_EOF;
266 }
267
268 /* read a single block; the default block size is 2230. */
269 size = (st->codecpar->block_align > 1) ? st->codecpar->block_align : 2230;
270 size = FFMIN(size, left);
271
272 ret = av_get_packet(s->pb, pkt, size);
273 if (ret < 0)
274 return ret;
275
276 pkt->stream_index = 0;
277 return ret;
278 }
279
280 AVInputFormat ff_xwma_demuxer = {
281 .name = "xwma",
282 .long_name = NULL_IF_CONFIG_SMALL("Microsoft xWMA"),
283 .priv_data_size = sizeof(XWMAContext),
284 .read_probe = xwma_probe,
285 .read_header = xwma_read_header,
286 .read_packet = xwma_read_packet,
287 };