Libav 0.7.1
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00001 /* 00002 * id Quake II CIN File Demuxer 00003 * Copyright (c) 2003 The ffmpeg Project 00004 * 00005 * This file is part of Libav. 00006 * 00007 * Libav is free software; you can redistribute it and/or 00008 * modify it under the terms of the GNU Lesser General Public 00009 * License as published by the Free Software Foundation; either 00010 * version 2.1 of the License, or (at your option) any later version. 00011 * 00012 * Libav is distributed in the hope that it will be useful, 00013 * but WITHOUT ANY WARRANTY; without even the implied warranty of 00014 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 00015 * Lesser General Public License for more details. 00016 * 00017 * You should have received a copy of the GNU Lesser General Public 00018 * License along with Libav; if not, write to the Free Software 00019 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 00020 */ 00021 00071 #include "libavutil/intreadwrite.h" 00072 #include "avformat.h" 00073 00074 #define HUFFMAN_TABLE_SIZE (64 * 1024) 00075 #define IDCIN_FPS 14 00076 00077 typedef struct IdcinDemuxContext { 00078 int video_stream_index; 00079 int audio_stream_index; 00080 int audio_chunk_size1; 00081 int audio_chunk_size2; 00082 00083 /* demux state variables */ 00084 int current_audio_chunk; 00085 int next_chunk_is_video; 00086 int audio_present; 00087 00088 int64_t pts; 00089 } IdcinDemuxContext; 00090 00091 static int idcin_probe(AVProbeData *p) 00092 { 00093 unsigned int number; 00094 00095 /* 00096 * This is what you could call a "probabilistic" file check: id CIN 00097 * files don't have a definite file signature. In lieu of such a marker, 00098 * perform sanity checks on the 5 32-bit header fields: 00099 * width, height: greater than 0, less than or equal to 1024 00100 * audio sample rate: greater than or equal to 8000, less than or 00101 * equal to 48000, or 0 for no audio 00102 * audio sample width (bytes/sample): 0 for no audio, or 1 or 2 00103 * audio channels: 0 for no audio, or 1 or 2 00104 */ 00105 00106 /* check we have enough data to do all checks, otherwise the 00107 0-padding may cause a wrong recognition */ 00108 if (p->buf_size < 20) 00109 return 0; 00110 00111 /* check the video width */ 00112 number = AV_RL32(&p->buf[0]); 00113 if ((number == 0) || (number > 1024)) 00114 return 0; 00115 00116 /* check the video height */ 00117 number = AV_RL32(&p->buf[4]); 00118 if ((number == 0) || (number > 1024)) 00119 return 0; 00120 00121 /* check the audio sample rate */ 00122 number = AV_RL32(&p->buf[8]); 00123 if ((number != 0) && ((number < 8000) | (number > 48000))) 00124 return 0; 00125 00126 /* check the audio bytes/sample */ 00127 number = AV_RL32(&p->buf[12]); 00128 if (number > 2) 00129 return 0; 00130 00131 /* check the audio channels */ 00132 number = AV_RL32(&p->buf[16]); 00133 if (number > 2) 00134 return 0; 00135 00136 /* return half certainly since this check is a bit sketchy */ 00137 return AVPROBE_SCORE_MAX / 2; 00138 } 00139 00140 static int idcin_read_header(AVFormatContext *s, 00141 AVFormatParameters *ap) 00142 { 00143 AVIOContext *pb = s->pb; 00144 IdcinDemuxContext *idcin = s->priv_data; 00145 AVStream *st; 00146 unsigned int width, height; 00147 unsigned int sample_rate, bytes_per_sample, channels; 00148 00149 /* get the 5 header parameters */ 00150 width = avio_rl32(pb); 00151 height = avio_rl32(pb); 00152 sample_rate = avio_rl32(pb); 00153 bytes_per_sample = avio_rl32(pb); 00154 channels = avio_rl32(pb); 00155 00156 st = av_new_stream(s, 0); 00157 if (!st) 00158 return AVERROR(ENOMEM); 00159 av_set_pts_info(st, 33, 1, IDCIN_FPS); 00160 idcin->video_stream_index = st->index; 00161 st->codec->codec_type = AVMEDIA_TYPE_VIDEO; 00162 st->codec->codec_id = CODEC_ID_IDCIN; 00163 st->codec->codec_tag = 0; /* no fourcc */ 00164 st->codec->width = width; 00165 st->codec->height = height; 00166 00167 /* load up the Huffman tables into extradata */ 00168 st->codec->extradata_size = HUFFMAN_TABLE_SIZE; 00169 st->codec->extradata = av_malloc(HUFFMAN_TABLE_SIZE); 00170 if (avio_read(pb, st->codec->extradata, HUFFMAN_TABLE_SIZE) != 00171 HUFFMAN_TABLE_SIZE) 00172 return AVERROR(EIO); 00173 00174 /* if sample rate is 0, assume no audio */ 00175 if (sample_rate) { 00176 idcin->audio_present = 1; 00177 st = av_new_stream(s, 0); 00178 if (!st) 00179 return AVERROR(ENOMEM); 00180 av_set_pts_info(st, 33, 1, IDCIN_FPS); 00181 idcin->audio_stream_index = st->index; 00182 st->codec->codec_type = AVMEDIA_TYPE_AUDIO; 00183 st->codec->codec_tag = 1; 00184 st->codec->channels = channels; 00185 st->codec->sample_rate = sample_rate; 00186 st->codec->bits_per_coded_sample = bytes_per_sample * 8; 00187 st->codec->bit_rate = sample_rate * bytes_per_sample * 8 * channels; 00188 st->codec->block_align = bytes_per_sample * channels; 00189 if (bytes_per_sample == 1) 00190 st->codec->codec_id = CODEC_ID_PCM_U8; 00191 else 00192 st->codec->codec_id = CODEC_ID_PCM_S16LE; 00193 00194 if (sample_rate % 14 != 0) { 00195 idcin->audio_chunk_size1 = (sample_rate / 14) * 00196 bytes_per_sample * channels; 00197 idcin->audio_chunk_size2 = (sample_rate / 14 + 1) * 00198 bytes_per_sample * channels; 00199 } else { 00200 idcin->audio_chunk_size1 = idcin->audio_chunk_size2 = 00201 (sample_rate / 14) * bytes_per_sample * channels; 00202 } 00203 idcin->current_audio_chunk = 0; 00204 } else 00205 idcin->audio_present = 1; 00206 00207 idcin->next_chunk_is_video = 1; 00208 idcin->pts = 0; 00209 00210 return 0; 00211 } 00212 00213 static int idcin_read_packet(AVFormatContext *s, 00214 AVPacket *pkt) 00215 { 00216 int ret; 00217 unsigned int command; 00218 unsigned int chunk_size; 00219 IdcinDemuxContext *idcin = s->priv_data; 00220 AVIOContext *pb = s->pb; 00221 int i; 00222 int palette_scale; 00223 unsigned char r, g, b; 00224 unsigned char palette_buffer[768]; 00225 uint32_t palette[256]; 00226 00227 if (s->pb->eof_reached) 00228 return AVERROR(EIO); 00229 00230 if (idcin->next_chunk_is_video) { 00231 command = avio_rl32(pb); 00232 if (command == 2) { 00233 return AVERROR(EIO); 00234 } else if (command == 1) { 00235 /* trigger a palette change */ 00236 if (avio_read(pb, palette_buffer, 768) != 768) 00237 return AVERROR(EIO); 00238 /* scale the palette as necessary */ 00239 palette_scale = 2; 00240 for (i = 0; i < 768; i++) 00241 if (palette_buffer[i] > 63) { 00242 palette_scale = 0; 00243 break; 00244 } 00245 00246 for (i = 0; i < 256; i++) { 00247 r = palette_buffer[i * 3 ] << palette_scale; 00248 g = palette_buffer[i * 3 + 1] << palette_scale; 00249 b = palette_buffer[i * 3 + 2] << palette_scale; 00250 palette[i] = (r << 16) | (g << 8) | (b); 00251 } 00252 } 00253 00254 chunk_size = avio_rl32(pb); 00255 /* skip the number of decoded bytes (always equal to width * height) */ 00256 avio_skip(pb, 4); 00257 chunk_size -= 4; 00258 ret= av_get_packet(pb, pkt, chunk_size); 00259 if (ret < 0) 00260 return ret; 00261 if (command == 1) { 00262 uint8_t *pal; 00263 00264 pal = av_packet_new_side_data(pkt, AV_PKT_DATA_PALETTE, 00265 AVPALETTE_SIZE); 00266 if (ret < 0) 00267 return ret; 00268 memcpy(pal, palette, AVPALETTE_SIZE); 00269 } 00270 pkt->stream_index = idcin->video_stream_index; 00271 pkt->pts = idcin->pts; 00272 } else { 00273 /* send out the audio chunk */ 00274 if (idcin->current_audio_chunk) 00275 chunk_size = idcin->audio_chunk_size2; 00276 else 00277 chunk_size = idcin->audio_chunk_size1; 00278 ret= av_get_packet(pb, pkt, chunk_size); 00279 if (ret < 0) 00280 return ret; 00281 pkt->stream_index = idcin->audio_stream_index; 00282 pkt->pts = idcin->pts; 00283 00284 idcin->current_audio_chunk ^= 1; 00285 idcin->pts++; 00286 } 00287 00288 if (idcin->audio_present) 00289 idcin->next_chunk_is_video ^= 1; 00290 00291 return ret; 00292 } 00293 00294 AVInputFormat ff_idcin_demuxer = { 00295 "idcin", 00296 NULL_IF_CONFIG_SMALL("id Cinematic format"), 00297 sizeof(IdcinDemuxContext), 00298 idcin_probe, 00299 idcin_read_header, 00300 idcin_read_packet, 00301 };