FFmpeg: libavformat/vqf.c Source File

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 
00025 typedef struct VqfContext {
00026     int frame_bit_len;
00027     uint8_t last_frame_bits;
00028     int remaining_bits;
00029 } VqfContext;
00030 
00031 static int vqf_probe(AVProbeData *probe_packet)
00032 {
00033     if (AV_RL32(probe_packet->buf) != MKTAG('T','W','I','N'))
00034         return 0;
00035 
00036     if (!memcmp(probe_packet->buf + 4, "97012000", 8))
00037         return AVPROBE_SCORE_MAX;
00038 
00039     if (!memcmp(probe_packet->buf + 4, "00052200", 8))
00040         return AVPROBE_SCORE_MAX;
00041 
00042     return AVPROBE_SCORE_MAX/2;
00043 }
00044 
00045 static void add_metadata(AVFormatContext *s, const char *tag,
00046                          unsigned int tag_len, unsigned int remaining)
00047 {
00048     int len = FFMIN(tag_len, remaining);
00049     char *buf;
00050 
00051     if (len == UINT_MAX)
00052         return;
00053 
00054     buf = av_malloc(len+1);
00055     if (!buf)
00056         return;
00057     get_buffer(s->pb, buf, len);
00058     buf[len] = 0;
00059     av_metadata_set2(&s->metadata, tag, buf, AV_METADATA_DONT_STRDUP_VAL);
00060 }
00061 
00062 static int vqf_read_header(AVFormatContext *s, AVFormatParameters *ap)
00063 {
00064     VqfContext *c = s->priv_data;
00065     AVStream *st  = av_new_stream(s, 0);
00066     int chunk_tag;
00067     int rate_flag = -1;
00068     int header_size;
00069     int read_bitrate = 0;
00070     int size;
00071 
00072     if (!st)
00073         return AVERROR(ENOMEM);
00074 
00075     url_fskip(s->pb, 12);
00076 
00077     header_size = get_be32(s->pb);
00078 
00079     st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
00080     st->codec->codec_id   = CODEC_ID_TWINVQ;
00081     st->start_time = 0;
00082 
00083     do {
00084         int len;
00085         chunk_tag = get_le32(s->pb);
00086 
00087         if (chunk_tag == MKTAG('D','A','T','A'))
00088             break;
00089 
00090         len = get_be32(s->pb);
00091 
00092         if ((unsigned) len > INT_MAX/2) {
00093             av_log(s, AV_LOG_ERROR, "Malformed header\n");
00094             return -1;
00095         }
00096 
00097         header_size -= 8;
00098 
00099         switch(chunk_tag){
00100         case MKTAG('C','O','M','M'):
00101             st->codec->channels = get_be32(s->pb) + 1;
00102             read_bitrate        = get_be32(s->pb);
00103             rate_flag           = get_be32(s->pb);
00104             url_fskip(s->pb, len-12);
00105 
00106             st->codec->bit_rate              = read_bitrate*1000;
00107             st->codec->bits_per_coded_sample = 16;
00108             break;
00109         case MKTAG('N','A','M','E'):
00110             add_metadata(s, "title"    , len, header_size);
00111             break;
00112         case MKTAG('(','c',')',' '):
00113             add_metadata(s, "copyright", len, header_size);
00114             break;
00115         case MKTAG('A','U','T','H'):
00116             add_metadata(s, "author"   , len, header_size);
00117             break;
00118         case MKTAG('A','L','B','M'):
00119             add_metadata(s, "album"    , len, header_size);
00120             break;
00121         case MKTAG('T','R','C','K'):
00122             add_metadata(s, "track"    , len, header_size);
00123             break;
00124         case MKTAG('C','O','M','T'):
00125             add_metadata(s, "comment"  , len, header_size);
00126             break;
00127         case MKTAG('F','I','L','E'):
00128             add_metadata(s, "filename" , len, header_size);
00129             break;
00130         case MKTAG('D','S','I','Z'):
00131             add_metadata(s, "size"     , len, header_size);
00132             break;
00133         case MKTAG('D','A','T','E'):
00134             add_metadata(s, "date"     , len, header_size);
00135             break;
00136         case MKTAG('G','E','N','R'):
00137             add_metadata(s, "genre"    , len, header_size);
00138             break;
00139         default:
00140             av_log(s, AV_LOG_ERROR, "Unknown chunk: %c%c%c%c\n",
00141                    ((char*)&chunk_tag)[0], ((char*)&chunk_tag)[1],
00142                    ((char*)&chunk_tag)[2], ((char*)&chunk_tag)[3]);
00143             url_fskip(s->pb, FFMIN(len, header_size));
00144             break;
00145         }
00146 
00147         header_size -= len;
00148 
00149     } while (header_size >= 0);
00150 
00151     switch (rate_flag) {
00152     case -1:
00153         av_log(s, AV_LOG_ERROR, "COMM tag not found!\n");
00154         return -1;
00155     case 44:
00156         st->codec->sample_rate = 44100;
00157         break;
00158     case 22:
00159         st->codec->sample_rate = 22050;
00160         break;
00161     case 11:
00162         st->codec->sample_rate = 11025;
00163         break;
00164     default:
00165         st->codec->sample_rate = rate_flag*1000;
00166         break;
00167     }
00168 
00169     switch (((st->codec->sample_rate/1000) << 8) +
00170             read_bitrate/st->codec->channels) {
00171     case (11<<8) + 8 :
00172     case (8 <<8) + 8 :
00173     case (11<<8) + 10:
00174     case (22<<8) + 32:
00175         size = 512;
00176         break;
00177     case (16<<8) + 16:
00178     case (22<<8) + 20:
00179     case (22<<8) + 24:
00180         size = 1024;
00181         break;
00182     case (44<<8) + 40:
00183     case (44<<8) + 48:
00184         size = 2048;
00185         break;
00186     default:
00187         av_log(s, AV_LOG_ERROR, "Mode not suported: %d Hz, %d kb/s.\n",
00188                st->codec->sample_rate, st->codec->bit_rate);
00189         return -1;
00190     }
00191     c->frame_bit_len = st->codec->bit_rate*size/st->codec->sample_rate;
00192     av_set_pts_info(st, 64, 1, st->codec->sample_rate);
00193 
00194     return 0;
00195 }
00196 
00197 static int vqf_read_packet(AVFormatContext *s, AVPacket *pkt)
00198 {
00199     VqfContext *c = s->priv_data;
00200     int ret;
00201     int size = (c->frame_bit_len - c->remaining_bits + 7)>>3;
00202 
00203     pkt->pos          = url_ftell(s->pb);
00204     pkt->stream_index = 0;
00205 
00206     if (av_new_packet(pkt, size+2) < 0)
00207         return AVERROR(EIO);
00208 
00209     pkt->data[0] = 8 - c->remaining_bits; // Number of bits to skip
00210     pkt->data[1] = c->last_frame_bits;
00211     ret = get_buffer(s->pb, pkt->data+2, size);
00212 
00213     if (ret<=0) {
00214         av_free_packet(pkt);
00215         return AVERROR(EIO);
00216     }
00217 
00218     c->last_frame_bits = pkt->data[size+1];
00219     c->remaining_bits  = (size << 3) - c->frame_bit_len + c->remaining_bits;
00220 
00221     return size+2;
00222 }
00223 
00224 static int vqf_read_seek(AVFormatContext *s,
00225                          int stream_index, int64_t timestamp, int flags)
00226 {
00227     VqfContext *c = s->priv_data;
00228     AVStream *st;
00229     int ret;
00230     int64_t pos;
00231 
00232     st = s->streams[stream_index];
00233     pos = av_rescale_rnd(timestamp * st->codec->bit_rate,
00234                          st->time_base.num,
00235                          st->time_base.den * (int64_t)c->frame_bit_len,
00236                          (flags & AVSEEK_FLAG_BACKWARD) ?
00237                                                    AV_ROUND_DOWN : AV_ROUND_UP);
00238     pos *= c->frame_bit_len;
00239 
00240     st->cur_dts = av_rescale(pos, st->time_base.den,
00241                              st->codec->bit_rate * (int64_t)st->time_base.num);
00242 
00243     if ((ret = url_fseek(s->pb, ((pos-7) >> 3) + s->data_offset, SEEK_SET)) < 0)
00244         return ret;
00245 
00246     c->remaining_bits = -7 - ((pos-7)&7);
00247     return 0;
00248 }
00249 
00250 AVInputFormat vqf_demuxer = {
00251     "vqf",
00252     NULL_IF_CONFIG_SMALL("Nippon Telegraph and Telephone Corporation (NTT) TwinVQ"),
00253     sizeof(VqfContext),
00254     vqf_probe,
00255     vqf_read_header,
00256     vqf_read_packet,
00257     NULL,
00258     vqf_read_seek,
00259     .extensions = "vqf",
00260 };