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libavformat/vqf.c

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00001 /*
00002  * VQF demuxer
00003  * Copyright (c) 2009 Vitor Sessak
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 
00022 #include "avformat.h"
00023 #include "libavutil/intreadwrite.h"
00024 #include "libavutil/dict.h"
00025 
00026 typedef struct VqfContext {
00027     int frame_bit_len;
00028     uint8_t last_frame_bits;
00029     int remaining_bits;
00030 } VqfContext;
00031 
00032 static int vqf_probe(AVProbeData *probe_packet)
00033 {
00034     if (AV_RL32(probe_packet->buf) != MKTAG('T','W','I','N'))
00035         return 0;
00036 
00037     if (!memcmp(probe_packet->buf + 4, "97012000", 8))
00038         return AVPROBE_SCORE_MAX;
00039 
00040     if (!memcmp(probe_packet->buf + 4, "00052200", 8))
00041         return AVPROBE_SCORE_MAX;
00042 
00043     return AVPROBE_SCORE_MAX/2;
00044 }
00045 
00046 static void add_metadata(AVFormatContext *s, const char *tag,
00047                          unsigned int tag_len, unsigned int remaining)
00048 {
00049     int len = FFMIN(tag_len, remaining);
00050     char *buf;
00051 
00052     if (len == UINT_MAX)
00053         return;
00054 
00055     buf = av_malloc(len+1);
00056     if (!buf)
00057         return;
00058     avio_read(s->pb, buf, len);
00059     buf[len] = 0;
00060     av_dict_set(&s->metadata, tag, buf, AV_DICT_DONT_STRDUP_VAL);
00061 }
00062 
00063 static int vqf_read_header(AVFormatContext *s, AVFormatParameters *ap)
00064 {
00065     VqfContext *c = s->priv_data;
00066     AVStream *st  = av_new_stream(s, 0);
00067     int chunk_tag;
00068     int rate_flag = -1;
00069     int header_size;
00070     int read_bitrate = 0;
00071     int size;
00072 
00073     if (!st)
00074         return AVERROR(ENOMEM);
00075 
00076     avio_skip(s->pb, 12);
00077 
00078     header_size = avio_rb32(s->pb);
00079 
00080     st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
00081     st->codec->codec_id   = CODEC_ID_TWINVQ;
00082     st->start_time = 0;
00083 
00084     do {
00085         int len;
00086         chunk_tag = avio_rl32(s->pb);
00087 
00088         if (chunk_tag == MKTAG('D','A','T','A'))
00089             break;
00090 
00091         len = avio_rb32(s->pb);
00092 
00093         if ((unsigned) len > INT_MAX/2) {
00094             av_log(s, AV_LOG_ERROR, "Malformed header\n");
00095             return -1;
00096         }
00097 
00098         header_size -= 8;
00099 
00100         switch(chunk_tag){
00101         case MKTAG('C','O','M','M'):
00102             st->codec->channels = avio_rb32(s->pb) + 1;
00103             read_bitrate        = avio_rb32(s->pb);
00104             rate_flag           = avio_rb32(s->pb);
00105             avio_skip(s->pb, len-12);
00106 
00107             st->codec->bit_rate              = read_bitrate*1000;
00108             st->codec->bits_per_coded_sample = 16;
00109             break;
00110         case MKTAG('N','A','M','E'):
00111             add_metadata(s, "title"    , len, header_size);
00112             break;
00113         case MKTAG('(','c',')',' '):
00114             add_metadata(s, "copyright", len, header_size);
00115             break;
00116         case MKTAG('A','U','T','H'):
00117             add_metadata(s, "author"   , len, header_size);
00118             break;
00119         case MKTAG('A','L','B','M'):
00120             add_metadata(s, "album"    , len, header_size);
00121             break;
00122         case MKTAG('T','R','C','K'):
00123             add_metadata(s, "track"    , len, header_size);
00124             break;
00125         case MKTAG('C','O','M','T'):
00126             add_metadata(s, "comment"  , len, header_size);
00127             break;
00128         case MKTAG('F','I','L','E'):
00129             add_metadata(s, "filename" , len, header_size);
00130             break;
00131         case MKTAG('D','S','I','Z'):
00132             add_metadata(s, "size"     , len, header_size);
00133             break;
00134         case MKTAG('D','A','T','E'):
00135             add_metadata(s, "date"     , len, header_size);
00136             break;
00137         case MKTAG('G','E','N','R'):
00138             add_metadata(s, "genre"    , len, header_size);
00139             break;
00140         default:
00141             av_log(s, AV_LOG_ERROR, "Unknown chunk: %c%c%c%c\n",
00142                    ((char*)&chunk_tag)[0], ((char*)&chunk_tag)[1],
00143                    ((char*)&chunk_tag)[2], ((char*)&chunk_tag)[3]);
00144             avio_skip(s->pb, FFMIN(len, header_size));
00145             break;
00146         }
00147 
00148         header_size -= len;
00149 
00150     } while (header_size >= 0);
00151 
00152     switch (rate_flag) {
00153     case -1:
00154         av_log(s, AV_LOG_ERROR, "COMM tag not found!\n");
00155         return -1;
00156     case 44:
00157         st->codec->sample_rate = 44100;
00158         break;
00159     case 22:
00160         st->codec->sample_rate = 22050;
00161         break;
00162     case 11:
00163         st->codec->sample_rate = 11025;
00164         break;
00165     default:
00166         st->codec->sample_rate = rate_flag*1000;
00167         break;
00168     }
00169 
00170     switch (((st->codec->sample_rate/1000) << 8) +
00171             read_bitrate/st->codec->channels) {
00172     case (11<<8) + 8 :
00173     case (8 <<8) + 8 :
00174     case (11<<8) + 10:
00175     case (22<<8) + 32:
00176         size = 512;
00177         break;
00178     case (16<<8) + 16:
00179     case (22<<8) + 20:
00180     case (22<<8) + 24:
00181         size = 1024;
00182         break;
00183     case (44<<8) + 40:
00184     case (44<<8) + 48:
00185         size = 2048;
00186         break;
00187     default:
00188         av_log(s, AV_LOG_ERROR, "Mode not suported: %d Hz, %d kb/s.\n",
00189                st->codec->sample_rate, st->codec->bit_rate);
00190         return -1;
00191     }
00192     c->frame_bit_len = st->codec->bit_rate*size/st->codec->sample_rate;
00193     av_set_pts_info(st, 64, 1, st->codec->sample_rate);
00194 
00195     return 0;
00196 }
00197 
00198 static int vqf_read_packet(AVFormatContext *s, AVPacket *pkt)
00199 {
00200     VqfContext *c = s->priv_data;
00201     int ret;
00202     int size = (c->frame_bit_len - c->remaining_bits + 7)>>3;
00203 
00204     pkt->pos          = avio_tell(s->pb);
00205     pkt->stream_index = 0;
00206 
00207     if (av_new_packet(pkt, size+2) < 0)
00208         return AVERROR(EIO);
00209 
00210     pkt->data[0] = 8 - c->remaining_bits; // Number of bits to skip
00211     pkt->data[1] = c->last_frame_bits;
00212     ret = avio_read(s->pb, pkt->data+2, size);
00213 
00214     if (ret<=0) {
00215         av_free_packet(pkt);
00216         return AVERROR(EIO);
00217     }
00218 
00219     c->last_frame_bits = pkt->data[size+1];
00220     c->remaining_bits  = (size << 3) - c->frame_bit_len + c->remaining_bits;
00221 
00222     return size+2;
00223 }
00224 
00225 static int vqf_read_seek(AVFormatContext *s,
00226                          int stream_index, int64_t timestamp, int flags)
00227 {
00228     VqfContext *c = s->priv_data;
00229     AVStream *st;
00230     int ret;
00231     int64_t pos;
00232 
00233     st = s->streams[stream_index];
00234     pos = av_rescale_rnd(timestamp * st->codec->bit_rate,
00235                          st->time_base.num,
00236                          st->time_base.den * (int64_t)c->frame_bit_len,
00237                          (flags & AVSEEK_FLAG_BACKWARD) ?
00238                                                    AV_ROUND_DOWN : AV_ROUND_UP);
00239     pos *= c->frame_bit_len;
00240 
00241     st->cur_dts = av_rescale(pos, st->time_base.den,
00242                              st->codec->bit_rate * (int64_t)st->time_base.num);
00243 
00244     if ((ret = avio_seek(s->pb, ((pos-7) >> 3) + s->data_offset, SEEK_SET)) < 0)
00245         return ret;
00246 
00247     c->remaining_bits = -7 - ((pos-7)&7);
00248     return 0;
00249 }
00250 
00251 AVInputFormat ff_vqf_demuxer = {
00252     "vqf",
00253     NULL_IF_CONFIG_SMALL("Nippon Telegraph and Telephone Corporation (NTT) TwinVQ"),
00254     sizeof(VqfContext),
00255     vqf_probe,
00256     vqf_read_header,
00257     vqf_read_packet,
00258     NULL,
00259     vqf_read_seek,
00260     .extensions = "vqf",
00261 };

Generated on Fri Feb 22 2013 07:24:32 for FFmpeg by  doxygen 1.7.1