Fix a possible use of an uninitialized pointer.
[libav.git] / libavformat / sierravmd.c
1 /*
2 * Sierra VMD Format Demuxer
3 * Copyright (c) 2004 The ffmpeg Project
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 /**
23 * @file sierravmd.c
24 * Sierra VMD file demuxer
25 * by Vladimir "VAG" Gneushev (vagsoft at mail.ru)
26 * for more information on the Sierra VMD file format, visit:
27 * http://www.pcisys.net/~melanson/codecs/
28 */
29
30 #include "avformat.h"
31
32 #define VMD_HEADER_SIZE 0x0330
33 #define BYTES_PER_FRAME_RECORD 16
34
35 typedef struct {
36 int stream_index;
37 offset_t frame_offset;
38 unsigned int frame_size;
39 int64_t pts;
40 int keyframe;
41 unsigned char frame_record[BYTES_PER_FRAME_RECORD];
42 } vmd_frame_t;
43
44 typedef struct VmdDemuxContext {
45 int video_stream_index;
46 int audio_stream_index;
47
48 unsigned int frame_count;
49 unsigned int frames_per_block;
50 vmd_frame_t *frame_table;
51 unsigned int current_frame;
52
53 int sample_rate;
54 int64_t audio_sample_counter;
55 int skiphdr;
56
57 unsigned char vmd_header[VMD_HEADER_SIZE];
58 } VmdDemuxContext;
59
60 static int vmd_probe(AVProbeData *p)
61 {
62 /* check if the first 2 bytes of the file contain the appropriate size
63 * of a VMD header chunk */
64 if (AV_RL16(&p->buf[0]) != VMD_HEADER_SIZE - 2)
65 return 0;
66
67 /* only return half certainty since this check is a bit sketchy */
68 return AVPROBE_SCORE_MAX / 2;
69 }
70
71 static int vmd_read_header(AVFormatContext *s,
72 AVFormatParameters *ap)
73 {
74 VmdDemuxContext *vmd = s->priv_data;
75 ByteIOContext *pb = s->pb;
76 AVStream *st = NULL, *vst;
77 unsigned int toc_offset;
78 unsigned char *raw_frame_table;
79 int raw_frame_table_size;
80 offset_t current_offset;
81 int i, j;
82 unsigned int total_frames;
83 int64_t pts_inc = 1;
84 int64_t current_video_pts = 0, current_audio_pts = 0;
85 unsigned char chunk[BYTES_PER_FRAME_RECORD];
86 int num, den;
87 int sound_buffers;
88
89 /* fetch the main header, including the 2 header length bytes */
90 url_fseek(pb, 0, SEEK_SET);
91 if (get_buffer(pb, vmd->vmd_header, VMD_HEADER_SIZE) != VMD_HEADER_SIZE)
92 return AVERROR(EIO);
93
94 /* start up the decoders */
95 vst = av_new_stream(s, 0);
96 if (!vst)
97 return AVERROR(ENOMEM);
98 av_set_pts_info(vst, 33, 1, 10);
99 vmd->video_stream_index = vst->index;
100 vst->codec->codec_type = CODEC_TYPE_VIDEO;
101 vst->codec->codec_id = CODEC_ID_VMDVIDEO;
102 vst->codec->codec_tag = 0; /* no fourcc */
103 vst->codec->width = AV_RL16(&vmd->vmd_header[12]);
104 vst->codec->height = AV_RL16(&vmd->vmd_header[14]);
105 vst->codec->extradata_size = VMD_HEADER_SIZE;
106 vst->codec->extradata = av_mallocz(VMD_HEADER_SIZE + FF_INPUT_BUFFER_PADDING_SIZE);
107 memcpy(vst->codec->extradata, vmd->vmd_header, VMD_HEADER_SIZE);
108
109 /* if sample rate is 0, assume no audio */
110 vmd->sample_rate = AV_RL16(&vmd->vmd_header[804]);
111 if (vmd->sample_rate) {
112 st = av_new_stream(s, 0);
113 if (!st)
114 return AVERROR(ENOMEM);
115 vmd->audio_stream_index = st->index;
116 st->codec->codec_type = CODEC_TYPE_AUDIO;
117 st->codec->codec_id = CODEC_ID_VMDAUDIO;
118 st->codec->codec_tag = 0; /* no fourcc */
119 st->codec->channels = (vmd->vmd_header[811] & 0x80) ? 2 : 1;
120 st->codec->sample_rate = vmd->sample_rate;
121 st->codec->block_align = AV_RL16(&vmd->vmd_header[806]);
122 if (st->codec->block_align & 0x8000) {
123 st->codec->bits_per_sample = 16;
124 st->codec->block_align = -(st->codec->block_align - 0x10000);
125 } else {
126 st->codec->bits_per_sample = 8;
127 }
128 st->codec->bit_rate = st->codec->sample_rate *
129 st->codec->bits_per_sample * st->codec->channels;
130
131 /* calculate pts */
132 num = st->codec->block_align;
133 den = st->codec->sample_rate * st->codec->channels;
134 av_reduce(&den, &num, den, num, (1UL<<31)-1);
135 av_set_pts_info(vst, 33, num, den);
136 av_set_pts_info(st, 33, num, den);
137 pts_inc = num;
138 }
139
140 toc_offset = AV_RL32(&vmd->vmd_header[812]);
141 vmd->frame_count = AV_RL16(&vmd->vmd_header[6]);
142 vmd->frames_per_block = AV_RL16(&vmd->vmd_header[18]);
143 url_fseek(pb, toc_offset, SEEK_SET);
144
145 raw_frame_table = NULL;
146 vmd->frame_table = NULL;
147 sound_buffers = AV_RL16(&vmd->vmd_header[808]);
148 raw_frame_table_size = vmd->frame_count * 6;
149 raw_frame_table = av_malloc(raw_frame_table_size);
150 if(vmd->frame_count * vmd->frames_per_block >= UINT_MAX / sizeof(vmd_frame_t)){
151 av_log(s, AV_LOG_ERROR, "vmd->frame_count * vmd->frames_per_block too large\n");
152 return -1;
153 }
154 vmd->frame_table = av_malloc((vmd->frame_count * vmd->frames_per_block + sound_buffers) * sizeof(vmd_frame_t));
155 if (!raw_frame_table || !vmd->frame_table) {
156 av_free(raw_frame_table);
157 av_free(vmd->frame_table);
158 return AVERROR(ENOMEM);
159 }
160 if (get_buffer(pb, raw_frame_table, raw_frame_table_size) !=
161 raw_frame_table_size) {
162 av_free(raw_frame_table);
163 av_free(vmd->frame_table);
164 return AVERROR(EIO);
165 }
166
167 total_frames = 0;
168 for (i = 0; i < vmd->frame_count; i++) {
169
170 current_offset = AV_RL32(&raw_frame_table[6 * i + 2]);
171
172 /* handle each entry in index block */
173 for (j = 0; j < vmd->frames_per_block; j++) {
174 int type;
175 uint32_t size;
176
177 get_buffer(pb, chunk, BYTES_PER_FRAME_RECORD);
178 type = chunk[0];
179 size = AV_RL32(&chunk[2]);
180 if(!size)
181 continue;
182 switch(type) {
183 case 1: /* Audio Chunk */
184 if (!st) break;
185 /* first audio chunk contains several audio buffers */
186 if(current_audio_pts){
187 vmd->frame_table[total_frames].frame_offset = current_offset;
188 vmd->frame_table[total_frames].stream_index = vmd->audio_stream_index;
189 vmd->frame_table[total_frames].frame_size = size;
190 memcpy(vmd->frame_table[total_frames].frame_record, chunk, BYTES_PER_FRAME_RECORD);
191 vmd->frame_table[total_frames].pts = current_audio_pts;
192 total_frames++;
193 current_audio_pts += pts_inc;
194 }else{
195 uint32_t flags;
196 int k;
197 int noff;
198 int64_t pos;
199
200 pos = url_ftell(pb);
201 url_fseek(pb, current_offset, SEEK_SET);
202 flags = get_le32(pb);
203 noff = 4;
204 url_fseek(pb, pos, SEEK_SET);
205 av_log(s, AV_LOG_DEBUG, "Sound mapping = %08X (%i bufs)\n", flags, sound_buffers);
206 for(k = 0; k < sound_buffers - 1; k++){
207 if(flags & 1) { /* silent block */
208 vmd->frame_table[total_frames].frame_size = 0;
209 }else{
210 vmd->frame_table[total_frames].frame_size = st->codec->block_align + (st->codec->block_align & 1);
211 }
212 noff += vmd->frame_table[total_frames].frame_size;
213 vmd->frame_table[total_frames].frame_offset = current_offset + noff;
214 vmd->frame_table[total_frames].stream_index = vmd->audio_stream_index;
215 memcpy(vmd->frame_table[total_frames].frame_record, chunk, BYTES_PER_FRAME_RECORD);
216 vmd->frame_table[total_frames].pts = current_audio_pts;
217 total_frames++;
218 current_audio_pts += pts_inc;
219 flags >>= 1;
220 }
221 }
222 break;
223 case 2: /* Video Chunk */
224 vmd->frame_table[total_frames].frame_offset = current_offset;
225 vmd->frame_table[total_frames].stream_index = vmd->video_stream_index;
226 vmd->frame_table[total_frames].frame_size = size;
227 memcpy(vmd->frame_table[total_frames].frame_record, chunk, BYTES_PER_FRAME_RECORD);
228 vmd->frame_table[total_frames].pts = current_video_pts;
229 total_frames++;
230 break;
231 }
232 current_offset += size;
233 }
234 current_video_pts += pts_inc;
235 }
236
237 av_free(raw_frame_table);
238
239 vmd->current_frame = 0;
240 vmd->frame_count = total_frames;
241
242 return 0;
243 }
244
245 static int vmd_read_packet(AVFormatContext *s,
246 AVPacket *pkt)
247 {
248 VmdDemuxContext *vmd = s->priv_data;
249 ByteIOContext *pb = s->pb;
250 int ret = 0;
251 vmd_frame_t *frame;
252
253 if (vmd->current_frame >= vmd->frame_count)
254 return AVERROR(EIO);
255
256 frame = &vmd->frame_table[vmd->current_frame];
257 /* position the stream (will probably be there already) */
258 url_fseek(pb, frame->frame_offset, SEEK_SET);
259
260 if (av_new_packet(pkt, frame->frame_size + BYTES_PER_FRAME_RECORD))
261 return AVERROR(ENOMEM);
262 pkt->pos= url_ftell(pb);
263 memcpy(pkt->data, frame->frame_record, BYTES_PER_FRAME_RECORD);
264 ret = get_buffer(pb, pkt->data + BYTES_PER_FRAME_RECORD,
265 frame->frame_size);
266
267 if (ret != frame->frame_size) {
268 av_free_packet(pkt);
269 ret = AVERROR(EIO);
270 }
271 pkt->stream_index = frame->stream_index;
272 pkt->pts = frame->pts;
273 av_log(NULL, AV_LOG_DEBUG, " dispatching %s frame with %d bytes and pts %"PRId64"\n",
274 (frame->frame_record[0] == 0x02) ? "video" : "audio",
275 frame->frame_size + BYTES_PER_FRAME_RECORD,
276 pkt->pts);
277
278 vmd->current_frame++;
279
280 return ret;
281 }
282
283 static int vmd_read_close(AVFormatContext *s)
284 {
285 VmdDemuxContext *vmd = s->priv_data;
286
287 av_free(vmd->frame_table);
288
289 return 0;
290 }
291
292 AVInputFormat vmd_demuxer = {
293 "vmd",
294 "Sierra VMD format",
295 sizeof(VmdDemuxContext),
296 vmd_probe,
297 vmd_read_header,
298 vmd_read_packet,
299 vmd_read_close,
300 };