1/*
2 * RL2 Format Demuxer
3 * Copyright (c) 2008 Sascha Sommer (saschasommer@freenet.de)
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/**
23 * RL2 file demuxer
24 * @file
25 * @author Sascha Sommer (saschasommer@freenet.de)
26 * @see http://wiki.multimedia.cx/index.php?title=RL2
27 *
28 * extradata:
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
33 */
34
35#include "libavutil/intreadwrite.h"
36#include "libavutil/mathematics.h"
37#include "avformat.h"
38#include "internal.h"
39
40#define EXTRADATA1_SIZE (6 + 256 * 3) ///< video base, clr, palette
41
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')
45
46typedef struct Rl2DemuxContext {
47    unsigned int index_pos[2];   ///< indexes in the sample tables
48} Rl2DemuxContext;
49
50
51/**
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
55 */
56static int rl2_probe(AVProbeData *p)
57{
58
59    if(AV_RB32(&p->buf[0]) != FORM_TAG)
60        return 0;
61
62    if(AV_RB32(&p->buf[8]) != RLV2_TAG &&
63        AV_RB32(&p->buf[8]) != RLV3_TAG)
64        return 0;
65
66    return AVPROBE_SCORE_MAX;
67}
68
69/**
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
74 */
75static av_cold int rl2_read_header(AVFormatContext *s,
76                            AVFormatParameters *ap)
77{
78    AVIOContext *pb = s->pb;
79    AVStream *st;
80    unsigned int frame_count;
81    unsigned int audio_frame_counter = 0;
82    unsigned int video_frame_counter = 0;
83    unsigned int back_size;
84    unsigned short sound_rate;
85    unsigned short rate;
86    unsigned short channels;
87    unsigned short def_sound_size;
88    unsigned int signature;
89    unsigned int pts_den = 11025; /* video only case */
90    unsigned int pts_num = 1103;
91    unsigned int* chunk_offset = NULL;
92    int* chunk_size = NULL;
93    int* audio_size = NULL;
94    int i;
95    int ret = 0;
96
97    avio_skip(pb,4);          /* skip FORM tag */
98    back_size = avio_rl32(pb); /**< get size of the background frame */
99    signature = avio_rb32(pb);
100    avio_skip(pb, 4);         /* data size */
101    frame_count = avio_rl32(pb);
102
103    /* disallow back_sizes and frame_counts that may lead to overflows later */
104    if(back_size > INT_MAX/2  || frame_count > INT_MAX / sizeof(uint32_t))
105        return AVERROR_INVALIDDATA;
106
107    avio_skip(pb, 2);         /* encoding mentod */
108    sound_rate = avio_rl16(pb);
109    rate = avio_rl16(pb);
110    channels = avio_rl16(pb);
111    def_sound_size = avio_rl16(pb);
112
113    /** setup video stream */
114    st = avformat_new_stream(s, NULL);
115    if(!st)
116         return AVERROR(ENOMEM);
117
118    st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
119    st->codec->codec_id = CODEC_ID_RL2;
120    st->codec->codec_tag = 0;  /* no fourcc */
121    st->codec->width = 320;
122    st->codec->height = 200;
123
124    /** allocate and fill extradata */
125    st->codec->extradata_size = EXTRADATA1_SIZE;
126
127    if(signature == RLV3_TAG && back_size > 0)
128        st->codec->extradata_size += back_size;
129
130    st->codec->extradata = av_mallocz(st->codec->extradata_size +
131                                          FF_INPUT_BUFFER_PADDING_SIZE);
132    if(!st->codec->extradata)
133        return AVERROR(ENOMEM);
134
135    if(avio_read(pb,st->codec->extradata,st->codec->extradata_size) !=
136                      st->codec->extradata_size)
137        return AVERROR(EIO);
138
139    /** setup audio stream if present */
140    if(sound_rate){
141        pts_num = def_sound_size;
142        pts_den = rate;
143
144        st = avformat_new_stream(s, NULL);
145        if (!st)
146            return AVERROR(ENOMEM);
147        st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
148        st->codec->codec_id = CODEC_ID_PCM_U8;
149        st->codec->codec_tag = 1;
150        st->codec->channels = channels;
151        st->codec->bits_per_coded_sample = 8;
152        st->codec->sample_rate = rate;
153        st->codec->bit_rate = st->codec->channels * st->codec->sample_rate *
154            st->codec->bits_per_coded_sample;
155        st->codec->block_align = st->codec->channels *
156            st->codec->bits_per_coded_sample / 8;
157        avpriv_set_pts_info(st,32,1,rate);
158    }
159
160    avpriv_set_pts_info(s->streams[0], 32, pts_num, pts_den);
161
162    chunk_size =   av_malloc(frame_count * sizeof(uint32_t));
163    audio_size =   av_malloc(frame_count * sizeof(uint32_t));
164    chunk_offset = av_malloc(frame_count * sizeof(uint32_t));
165
166    if(!chunk_size || !audio_size || !chunk_offset){
167        av_free(chunk_size);
168        av_free(audio_size);
169        av_free(chunk_offset);
170        return AVERROR(ENOMEM);
171    }
172
173    /** read offset and size tables */
174    for(i=0; i < frame_count;i++)
175        chunk_size[i] = avio_rl32(pb);
176    for(i=0; i < frame_count;i++)
177        chunk_offset[i] = avio_rl32(pb);
178    for(i=0; i < frame_count;i++)
179        audio_size[i] = avio_rl32(pb) & 0xFFFF;
180
181    /** build the sample index */
182    for(i=0;i<frame_count;i++){
183        if(chunk_size[i] < 0 || audio_size[i] > chunk_size[i]){
184            ret = AVERROR_INVALIDDATA;
185            break;
186        }
187
188        if(sound_rate && audio_size[i]){
189            av_add_index_entry(s->streams[1], chunk_offset[i],
190                audio_frame_counter,audio_size[i], 0, AVINDEX_KEYFRAME);
191            audio_frame_counter += audio_size[i] / channels;
192        }
193        av_add_index_entry(s->streams[0], chunk_offset[i] + audio_size[i],
194            video_frame_counter,chunk_size[i]-audio_size[i],0,AVINDEX_KEYFRAME);
195        ++video_frame_counter;
196    }
197
198
199    av_free(chunk_size);
200    av_free(audio_size);
201    av_free(chunk_offset);
202
203    return ret;
204}
205
206/**
207 * read a single audio or video packet
208 * @param s demuxer context
209 * @param pkt the packet to be filled
210 * @return 0 on success, AVERROR otherwise
211 */
212static int rl2_read_packet(AVFormatContext *s,
213                            AVPacket *pkt)
214{
215    Rl2DemuxContext *rl2 = s->priv_data;
216    AVIOContext *pb = s->pb;
217    AVIndexEntry *sample = NULL;
218    int i;
219    int ret = 0;
220    int stream_id = -1;
221    int64_t pos = INT64_MAX;
222
223    /** check if there is a valid video or audio entry that can be used */
224    for(i=0; i<s->nb_streams; i++){
225        if(rl2->index_pos[i] < s->streams[i]->nb_index_entries
226              && s->streams[i]->index_entries[ rl2->index_pos[i] ].pos < pos){
227            sample = &s->streams[i]->index_entries[ rl2->index_pos[i] ];
228            pos= sample->pos;
229            stream_id= i;
230        }
231    }
232
233    if(stream_id == -1)
234        return AVERROR(EIO);
235
236    ++rl2->index_pos[stream_id];
237
238    /** position the stream (will probably be there anyway) */
239    avio_seek(pb, sample->pos, SEEK_SET);
240
241    /** fill the packet */
242    ret = av_get_packet(pb, pkt, sample->size);
243    if(ret != sample->size){
244        av_free_packet(pkt);
245        return AVERROR(EIO);
246    }
247
248    pkt->stream_index = stream_id;
249    pkt->pts = sample->timestamp;
250
251    return ret;
252}
253
254/**
255 * seek to a new timestamp
256 * @param s demuxer context
257 * @param stream_index index of the stream that should be seeked
258 * @param timestamp wanted timestamp
259 * @param flags direction and seeking mode
260 * @return 0 on success, -1 otherwise
261 */
262static int rl2_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
263{
264    AVStream *st = s->streams[stream_index];
265    Rl2DemuxContext *rl2 = s->priv_data;
266    int i;
267    int index = av_index_search_timestamp(st, timestamp, flags);
268    if(index < 0)
269        return -1;
270
271    rl2->index_pos[stream_index] = index;
272    timestamp = st->index_entries[index].timestamp;
273
274    for(i=0; i < s->nb_streams; i++){
275        AVStream *st2 = s->streams[i];
276        index = av_index_search_timestamp(st2,
277                    av_rescale_q(timestamp, st->time_base, st2->time_base),
278                    flags | AVSEEK_FLAG_BACKWARD);
279
280        if(index < 0)
281            index = 0;
282
283        rl2->index_pos[i] = index;
284    }
285
286    return 0;
287}
288
289AVInputFormat ff_rl2_demuxer = {
290    .name           = "rl2",
291    .long_name      = NULL_IF_CONFIG_SMALL("RL2 format"),
292    .priv_data_size = sizeof(Rl2DemuxContext),
293    .read_probe     = rl2_probe,
294    .read_header    = rl2_read_header,
295    .read_packet    = rl2_read_packet,
296    .read_seek      = rl2_read_seek,
297};
298
299