3 * Copyright (c) 2008 Sascha Sommer (saschasommer@freenet.de)
5 * This file is part of Libav.
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.
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.
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
25 * @author Sascha Sommer (saschasommer@freenet.de)
26 * @see http://wiki.multimedia.cx/index.php?title=RL2
29 * 2 byte le initial drawing offset within 320x200 viewport
30 * 4 byte le number of used colors
31 * 256 * 3 bytes rgb palette
32 * optional background_frame
35 #include "libavutil/intreadwrite.h"
36 #include "libavutil/mathematics.h"
40 #define EXTRADATA1_SIZE (6 + 256 * 3) ///< video base, clr, palette
42 #define FORM_TAG MKBETAG('F', 'O', 'R', 'M')
43 #define RLV2_TAG MKBETAG('R', 'L', 'V', '2')
44 #define RLV3_TAG MKBETAG('R', 'L', 'V', '3')
46 typedef struct Rl2DemuxContext {
47 unsigned int index_pos[2]; ///< indexes in the sample tables
52 * check if the file is in rl2 format
53 * @param p probe buffer
54 * @return 0 when the probe buffer does not contain rl2 data, > 0 otherwise
56 static int rl2_probe(AVProbeData *p)
59 if(AV_RB32(&p->buf[0]) != FORM_TAG)
62 if(AV_RB32(&p->buf[8]) != RLV2_TAG &&
63 AV_RB32(&p->buf[8]) != RLV3_TAG)
66 return AVPROBE_SCORE_MAX;
70 * read rl2 header data and setup the avstreams
71 * @param s demuxer context
72 * @return 0 on success, AVERROR otherwise
74 static av_cold int rl2_read_header(AVFormatContext *s)
76 AVIOContext *pb = s->pb;
78 unsigned int frame_count;
79 unsigned int audio_frame_counter = 0;
80 unsigned int video_frame_counter = 0;
81 unsigned int back_size;
82 unsigned short sound_rate;
84 unsigned short channels;
85 unsigned short def_sound_size;
86 unsigned int signature;
87 unsigned int pts_den = 11025; /* video only case */
88 unsigned int pts_num = 1103;
89 unsigned int* chunk_offset = NULL;
90 int* chunk_size = NULL;
91 int* audio_size = NULL;
95 avio_skip(pb,4); /* skip FORM tag */
96 back_size = avio_rl32(pb); /**< get size of the background frame */
97 signature = avio_rb32(pb);
98 avio_skip(pb, 4); /* data size */
99 frame_count = avio_rl32(pb);
101 /* disallow back_sizes and frame_counts that may lead to overflows later */
102 if(back_size > INT_MAX/2 || frame_count > INT_MAX / sizeof(uint32_t))
103 return AVERROR_INVALIDDATA;
105 avio_skip(pb, 2); /* encoding mentod */
106 sound_rate = avio_rl16(pb);
107 rate = avio_rl16(pb);
108 channels = avio_rl16(pb);
109 def_sound_size = avio_rl16(pb);
111 /** setup video stream */
112 st = avformat_new_stream(s, NULL);
114 return AVERROR(ENOMEM);
116 st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
117 st->codec->codec_id = CODEC_ID_RL2;
118 st->codec->codec_tag = 0; /* no fourcc */
119 st->codec->width = 320;
120 st->codec->height = 200;
122 /** allocate and fill extradata */
123 st->codec->extradata_size = EXTRADATA1_SIZE;
125 if(signature == RLV3_TAG && back_size > 0)
126 st->codec->extradata_size += back_size;
128 st->codec->extradata = av_mallocz(st->codec->extradata_size +
129 FF_INPUT_BUFFER_PADDING_SIZE);
130 if(!st->codec->extradata)
131 return AVERROR(ENOMEM);
133 if(avio_read(pb,st->codec->extradata,st->codec->extradata_size) !=
134 st->codec->extradata_size)
137 /** setup audio stream if present */
139 pts_num = def_sound_size;
142 st = avformat_new_stream(s, NULL);
144 return AVERROR(ENOMEM);
145 st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
146 st->codec->codec_id = CODEC_ID_PCM_U8;
147 st->codec->codec_tag = 1;
148 st->codec->channels = channels;
149 st->codec->bits_per_coded_sample = 8;
150 st->codec->sample_rate = rate;
151 st->codec->bit_rate = st->codec->channels * st->codec->sample_rate *
152 st->codec->bits_per_coded_sample;
153 st->codec->block_align = st->codec->channels *
154 st->codec->bits_per_coded_sample / 8;
155 avpriv_set_pts_info(st,32,1,rate);
158 avpriv_set_pts_info(s->streams[0], 32, pts_num, pts_den);
160 chunk_size = av_malloc(frame_count * sizeof(uint32_t));
161 audio_size = av_malloc(frame_count * sizeof(uint32_t));
162 chunk_offset = av_malloc(frame_count * sizeof(uint32_t));
164 if(!chunk_size || !audio_size || !chunk_offset){
167 av_free(chunk_offset);
168 return AVERROR(ENOMEM);
171 /** read offset and size tables */
172 for(i=0; i < frame_count;i++)
173 chunk_size[i] = avio_rl32(pb);
174 for(i=0; i < frame_count;i++)
175 chunk_offset[i] = avio_rl32(pb);
176 for(i=0; i < frame_count;i++)
177 audio_size[i] = avio_rl32(pb) & 0xFFFF;
179 /** build the sample index */
180 for(i=0;i<frame_count;i++){
181 if(chunk_size[i] < 0 || audio_size[i] > chunk_size[i]){
182 ret = AVERROR_INVALIDDATA;
186 if(sound_rate && audio_size[i]){
187 av_add_index_entry(s->streams[1], chunk_offset[i],
188 audio_frame_counter,audio_size[i], 0, AVINDEX_KEYFRAME);
189 audio_frame_counter += audio_size[i] / channels;
191 av_add_index_entry(s->streams[0], chunk_offset[i] + audio_size[i],
192 video_frame_counter,chunk_size[i]-audio_size[i],0,AVINDEX_KEYFRAME);
193 ++video_frame_counter;
199 av_free(chunk_offset);
205 * read a single audio or video packet
206 * @param s demuxer context
207 * @param pkt the packet to be filled
208 * @return 0 on success, AVERROR otherwise
210 static int rl2_read_packet(AVFormatContext *s,
213 Rl2DemuxContext *rl2 = s->priv_data;
214 AVIOContext *pb = s->pb;
215 AVIndexEntry *sample = NULL;
219 int64_t pos = INT64_MAX;
221 /** check if there is a valid video or audio entry that can be used */
222 for(i=0; i<s->nb_streams; i++){
223 if(rl2->index_pos[i] < s->streams[i]->nb_index_entries
224 && s->streams[i]->index_entries[ rl2->index_pos[i] ].pos < pos){
225 sample = &s->streams[i]->index_entries[ rl2->index_pos[i] ];
234 ++rl2->index_pos[stream_id];
236 /** position the stream (will probably be there anyway) */
237 avio_seek(pb, sample->pos, SEEK_SET);
239 /** fill the packet */
240 ret = av_get_packet(pb, pkt, sample->size);
241 if(ret != sample->size){
246 pkt->stream_index = stream_id;
247 pkt->pts = sample->timestamp;
253 * seek to a new timestamp
254 * @param s demuxer context
255 * @param stream_index index of the stream that should be seeked
256 * @param timestamp wanted timestamp
257 * @param flags direction and seeking mode
258 * @return 0 on success, -1 otherwise
260 static int rl2_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
262 AVStream *st = s->streams[stream_index];
263 Rl2DemuxContext *rl2 = s->priv_data;
265 int index = av_index_search_timestamp(st, timestamp, flags);
269 rl2->index_pos[stream_index] = index;
270 timestamp = st->index_entries[index].timestamp;
272 for(i=0; i < s->nb_streams; i++){
273 AVStream *st2 = s->streams[i];
274 index = av_index_search_timestamp(st2,
275 av_rescale_q(timestamp, st->time_base, st2->time_base),
276 flags | AVSEEK_FLAG_BACKWARD);
281 rl2->index_pos[i] = index;
287 AVInputFormat ff_rl2_demuxer = {
289 .long_name = NULL_IF_CONFIG_SMALL("RL2 format"),
290 .priv_data_size = sizeof(Rl2DemuxContext),
291 .read_probe = rl2_probe,
292 .read_header = rl2_read_header,
293 .read_packet = rl2_read_packet,
294 .read_seek = rl2_read_seek,