3 * Copyright (c) 2008 Sascha Sommer (saschasommer@freenet.de)
5 * This file is part of FFmpeg.
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.
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.
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
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 * @param ap format parameters
73 * @return 0 on success, AVERROR otherwise
75 static av_cold int rl2_read_header(AVFormatContext *s)
77 AVIOContext *pb = s->pb;
79 unsigned int frame_count;
80 unsigned int audio_frame_counter = 0;
81 unsigned int video_frame_counter = 0;
82 unsigned int back_size;
83 unsigned short sound_rate;
85 unsigned short channels;
86 unsigned short def_sound_size;
87 unsigned int signature;
88 unsigned int pts_den = 11025; /* video only case */
89 unsigned int pts_num = 1103;
90 unsigned int* chunk_offset = NULL;
91 int* chunk_size = NULL;
92 int* audio_size = NULL;
96 avio_skip(pb,4); /* skip FORM tag */
97 back_size = avio_rl32(pb); /**< get size of the background frame */
98 signature = avio_rb32(pb);
99 avio_skip(pb, 4); /* data size */
100 frame_count = avio_rl32(pb);
102 /* disallow back_sizes and frame_counts that may lead to overflows later */
103 if(back_size > INT_MAX/2 || frame_count > INT_MAX / sizeof(uint32_t))
104 return AVERROR_INVALIDDATA;
106 avio_skip(pb, 2); /* encoding mentod */
107 sound_rate = avio_rl16(pb);
108 rate = avio_rl16(pb);
109 channels = avio_rl16(pb);
110 def_sound_size = avio_rl16(pb);
112 /** setup video stream */
113 st = avformat_new_stream(s, NULL);
115 return AVERROR(ENOMEM);
117 st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
118 st->codec->codec_id = CODEC_ID_RL2;
119 st->codec->codec_tag = 0; /* no fourcc */
120 st->codec->width = 320;
121 st->codec->height = 200;
123 /** allocate and fill extradata */
124 st->codec->extradata_size = EXTRADATA1_SIZE;
126 if(signature == RLV3_TAG && back_size > 0)
127 st->codec->extradata_size += back_size;
129 st->codec->extradata = av_mallocz(st->codec->extradata_size +
130 FF_INPUT_BUFFER_PADDING_SIZE);
131 if(!st->codec->extradata)
132 return AVERROR(ENOMEM);
134 if(avio_read(pb,st->codec->extradata,st->codec->extradata_size) !=
135 st->codec->extradata_size)
138 /** setup audio stream if present */
141 return AVERROR_INVALIDDATA;
143 pts_num = def_sound_size;
146 st = avformat_new_stream(s, NULL);
148 return AVERROR(ENOMEM);
149 st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
150 st->codec->codec_id = CODEC_ID_PCM_U8;
151 st->codec->codec_tag = 1;
152 st->codec->channels = channels;
153 st->codec->bits_per_coded_sample = 8;
154 st->codec->sample_rate = rate;
155 st->codec->bit_rate = st->codec->channels * st->codec->sample_rate *
156 st->codec->bits_per_coded_sample;
157 st->codec->block_align = st->codec->channels *
158 st->codec->bits_per_coded_sample / 8;
159 avpriv_set_pts_info(st,32,1,rate);
162 avpriv_set_pts_info(s->streams[0], 32, pts_num, pts_den);
164 chunk_size = av_malloc(frame_count * sizeof(uint32_t));
165 audio_size = av_malloc(frame_count * sizeof(uint32_t));
166 chunk_offset = av_malloc(frame_count * sizeof(uint32_t));
168 if(!chunk_size || !audio_size || !chunk_offset){
171 av_free(chunk_offset);
172 return AVERROR(ENOMEM);
175 /** read offset and size tables */
176 for(i=0; i < frame_count;i++)
177 chunk_size[i] = avio_rl32(pb);
178 for(i=0; i < frame_count;i++)
179 chunk_offset[i] = avio_rl32(pb);
180 for(i=0; i < frame_count;i++)
181 audio_size[i] = avio_rl32(pb) & 0xFFFF;
183 /** build the sample index */
184 for(i=0;i<frame_count;i++){
185 if(chunk_size[i] < 0 || audio_size[i] > chunk_size[i]){
186 ret = AVERROR_INVALIDDATA;
190 if(sound_rate && audio_size[i]){
191 av_add_index_entry(s->streams[1], chunk_offset[i],
192 audio_frame_counter,audio_size[i], 0, AVINDEX_KEYFRAME);
193 audio_frame_counter += audio_size[i] / channels;
195 av_add_index_entry(s->streams[0], chunk_offset[i] + audio_size[i],
196 video_frame_counter,chunk_size[i]-audio_size[i],0,AVINDEX_KEYFRAME);
197 ++video_frame_counter;
203 av_free(chunk_offset);
209 * read a single audio or video packet
210 * @param s demuxer context
211 * @param pkt the packet to be filled
212 * @return 0 on success, AVERROR otherwise
214 static int rl2_read_packet(AVFormatContext *s,
217 Rl2DemuxContext *rl2 = s->priv_data;
218 AVIOContext *pb = s->pb;
219 AVIndexEntry *sample = NULL;
223 int64_t pos = INT64_MAX;
225 /** check if there is a valid video or audio entry that can be used */
226 for(i=0; i<s->nb_streams; i++){
227 if(rl2->index_pos[i] < s->streams[i]->nb_index_entries
228 && s->streams[i]->index_entries[ rl2->index_pos[i] ].pos < pos){
229 sample = &s->streams[i]->index_entries[ rl2->index_pos[i] ];
238 ++rl2->index_pos[stream_id];
240 /** position the stream (will probably be there anyway) */
241 avio_seek(pb, sample->pos, SEEK_SET);
243 /** fill the packet */
244 ret = av_get_packet(pb, pkt, sample->size);
245 if(ret != sample->size){
250 pkt->stream_index = stream_id;
251 pkt->pts = sample->timestamp;
257 * seek to a new timestamp
258 * @param s demuxer context
259 * @param stream_index index of the stream that should be seeked
260 * @param timestamp wanted timestamp
261 * @param flags direction and seeking mode
262 * @return 0 on success, -1 otherwise
264 static int rl2_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
266 AVStream *st = s->streams[stream_index];
267 Rl2DemuxContext *rl2 = s->priv_data;
269 int index = av_index_search_timestamp(st, timestamp, flags);
273 rl2->index_pos[stream_index] = index;
274 timestamp = st->index_entries[index].timestamp;
276 for(i=0; i < s->nb_streams; i++){
277 AVStream *st2 = s->streams[i];
278 index = av_index_search_timestamp(st2,
279 av_rescale_q(timestamp, st->time_base, st2->time_base),
280 flags | AVSEEK_FLAG_BACKWARD);
285 rl2->index_pos[i] = index;
291 AVInputFormat ff_rl2_demuxer = {
293 .long_name = NULL_IF_CONFIG_SMALL("RL2 format"),
294 .priv_data_size = sizeof(Rl2DemuxContext),
295 .read_probe = rl2_probe,
296 .read_header = rl2_read_header,
297 .read_packet = rl2_read_packet,
298 .read_seek = rl2_read_seek,