FFmpeg: libavformat/idcin.c Source File

00001 /*
00002  * id Quake II CIN File Demuxer
00003  * Copyright (c) 2003 The ffmpeg Project
00004  *
00005  * This file is part of FFmpeg.
00006  *
00007  * FFmpeg 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  * FFmpeg 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 FFmpeg; 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 #include "internal.h"
00074 
00075 #define HUFFMAN_TABLE_SIZE (64 * 1024)
00076 #define IDCIN_FPS 14
00077 
00078 typedef struct IdcinDemuxContext {
00079     int video_stream_index;
00080     int audio_stream_index;
00081     int audio_chunk_size1;
00082     int audio_chunk_size2;
00083 
00084     /* demux state variables */
00085     int current_audio_chunk;
00086     int next_chunk_is_video;
00087     int audio_present;
00088 
00089     int64_t pts;
00090 } IdcinDemuxContext;
00091 
00092 static int idcin_probe(AVProbeData *p)
00093 {
00094     unsigned int number;
00095 
00096     /*
00097      * This is what you could call a "probabilistic" file check: id CIN
00098      * files don't have a definite file signature. In lieu of such a marker,
00099      * perform sanity checks on the 5 32-bit header fields:
00100      *  width, height: greater than 0, less than or equal to 1024
00101      * audio sample rate: greater than or equal to 8000, less than or
00102      *  equal to 48000, or 0 for no audio
00103      * audio sample width (bytes/sample): 0 for no audio, or 1 or 2
00104      * audio channels: 0 for no audio, or 1 or 2
00105      */
00106 
00107     /* check we have enough data to do all checks, otherwise the
00108        0-padding may cause a wrong recognition */
00109     if (p->buf_size < 20)
00110         return 0;
00111 
00112     /* check the video width */
00113     number = AV_RL32(&p->buf[0]);
00114     if ((number == 0) || (number > 1024))
00115        return 0;
00116 
00117     /* check the video height */
00118     number = AV_RL32(&p->buf[4]);
00119     if ((number == 0) || (number > 1024))
00120        return 0;
00121 
00122     /* check the audio sample rate */
00123     number = AV_RL32(&p->buf[8]);
00124     if ((number != 0) && ((number < 8000) | (number > 48000)))
00125         return 0;
00126 
00127     /* check the audio bytes/sample */
00128     number = AV_RL32(&p->buf[12]);
00129     if (number > 2)
00130         return 0;
00131 
00132     /* check the audio channels */
00133     number = AV_RL32(&p->buf[16]);
00134     if (number > 2)
00135         return 0;
00136 
00137     /* return half certainly since this check is a bit sketchy */
00138     return AVPROBE_SCORE_MAX / 2;
00139 }
00140 
00141 static int idcin_read_header(AVFormatContext *s)
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 = avformat_new_stream(s, NULL);
00157     if (!st)
00158         return AVERROR(ENOMEM);
00159     avpriv_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 = avformat_new_stream(s, NULL);
00178         if (!st)
00179             return AVERROR(ENOMEM);
00180         avpriv_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 (url_feof(s->pb))
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] = (0xFFU << 24) | (r << 16) | (g << 8) | (b);
00251                 if (palette_scale == 2)
00252                     palette[i] |= palette[i] >> 6 & 0x30303;
00253             }
00254         }
00255 
00256         chunk_size = avio_rl32(pb);
00257         /* skip the number of decoded bytes (always equal to width * height) */
00258         avio_skip(pb, 4);
00259         chunk_size -= 4;
00260         ret= av_get_packet(pb, pkt, chunk_size);
00261         if (ret < 0)
00262             return ret;
00263         if (command == 1) {
00264             uint8_t *pal;
00265 
00266             pal = av_packet_new_side_data(pkt, AV_PKT_DATA_PALETTE,
00267                                           AVPALETTE_SIZE);
00268             if (!pal)
00269                 return AVERROR(ENOMEM);
00270             memcpy(pal, palette, AVPALETTE_SIZE);
00271         }
00272         pkt->stream_index = idcin->video_stream_index;
00273         pkt->pts = idcin->pts;
00274     } else {
00275         /* send out the audio chunk */
00276         if (idcin->current_audio_chunk)
00277             chunk_size = idcin->audio_chunk_size2;
00278         else
00279             chunk_size = idcin->audio_chunk_size1;
00280         ret= av_get_packet(pb, pkt, chunk_size);
00281         if (ret < 0)
00282             return ret;
00283         pkt->stream_index = idcin->audio_stream_index;
00284         pkt->pts = idcin->pts;
00285 
00286         idcin->current_audio_chunk ^= 1;
00287         idcin->pts++;
00288     }
00289 
00290     if (idcin->audio_present)
00291         idcin->next_chunk_is_video ^= 1;
00292 
00293     return ret;
00294 }
00295 
00296 AVInputFormat ff_idcin_demuxer = {
00297     .name           = "idcin",
00298     .long_name      = NULL_IF_CONFIG_SMALL("id Cinematic format"),
00299     .priv_data_size = sizeof(IdcinDemuxContext),
00300     .read_probe     = idcin_probe,
00301     .read_header    = idcin_read_header,
00302     .read_packet    = idcin_read_packet,
00303 };