Libav 0.7.1
libavformat/wv.c
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00001 /*
00002  * WavPack demuxer
00003  * Copyright (c) 2006,2011 Konstantin Shishkov
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 
00022 #include "libavutil/audioconvert.h"
00023 #include "libavutil/intreadwrite.h"
00024 #include "libavutil/dict.h"
00025 #include "avformat.h"
00026 #include "apetag.h"
00027 #include "id3v1.h"
00028 
00029 // specs say that maximum block size is 1Mb
00030 #define WV_BLOCK_LIMIT 1047576
00031 
00032 #define WV_EXTRA_SIZE 12
00033 
00034 #define WV_START_BLOCK  0x0800
00035 #define WV_END_BLOCK    0x1000
00036 #define WV_SINGLE_BLOCK (WV_START_BLOCK | WV_END_BLOCK)
00037 
00038 enum WV_FLAGS{
00039     WV_MONO   = 0x0004,
00040     WV_HYBRID = 0x0008,
00041     WV_JOINT  = 0x0010,
00042     WV_CROSSD = 0x0020,
00043     WV_HSHAPE = 0x0040,
00044     WV_FLOAT  = 0x0080,
00045     WV_INT32  = 0x0100,
00046     WV_HBR    = 0x0200,
00047     WV_HBAL   = 0x0400,
00048     WV_MCINIT = 0x0800,
00049     WV_MCEND  = 0x1000,
00050 };
00051 
00052 static const int wv_rates[16] = {
00053      6000,  8000,  9600, 11025, 12000, 16000, 22050, 24000,
00054     32000, 44100, 48000, 64000, 88200, 96000, 192000, -1
00055 };
00056 
00057 typedef struct{
00058     uint32_t blksize, flags;
00059     int rate, chan, bpp;
00060     uint32_t chmask;
00061     uint32_t samples, soff;
00062     int multichannel;
00063     int block_parsed;
00064     uint8_t extra[WV_EXTRA_SIZE];
00065     int64_t pos;
00066 }WVContext;
00067 
00068 static int wv_probe(AVProbeData *p)
00069 {
00070     /* check file header */
00071     if (p->buf_size <= 32)
00072         return 0;
00073     if (p->buf[0] == 'w' && p->buf[1] == 'v' &&
00074         p->buf[2] == 'p' && p->buf[3] == 'k')
00075         return AVPROBE_SCORE_MAX;
00076     else
00077         return 0;
00078 }
00079 
00080 static int wv_read_block_header(AVFormatContext *ctx, AVIOContext *pb, int append)
00081 {
00082     WVContext *wc = ctx->priv_data;
00083     uint32_t tag, ver;
00084     int size;
00085     int rate, bpp, chan;
00086     uint32_t chmask;
00087 
00088     wc->pos = avio_tell(pb);
00089     if(!append){
00090         tag = avio_rl32(pb);
00091         if (tag != MKTAG('w', 'v', 'p', 'k'))
00092             return -1;
00093         size = avio_rl32(pb);
00094         if(size < 24 || size > WV_BLOCK_LIMIT){
00095             av_log(ctx, AV_LOG_ERROR, "Incorrect block size %i\n", size);
00096             return -1;
00097         }
00098         wc->blksize = size;
00099         ver = avio_rl16(pb);
00100         if(ver < 0x402 || ver > 0x410){
00101             av_log(ctx, AV_LOG_ERROR, "Unsupported version %03X\n", ver);
00102             return -1;
00103         }
00104         avio_r8(pb); // track no
00105         avio_r8(pb); // track sub index
00106         wc->samples = avio_rl32(pb); // total samples in file
00107         wc->soff = avio_rl32(pb); // offset in samples of current block
00108         avio_read(pb, wc->extra, WV_EXTRA_SIZE);
00109     }else{
00110         size = wc->blksize;
00111     }
00112     wc->flags = AV_RL32(wc->extra + 4);
00113     // blocks with zero samples don't contain actual audio information and should be ignored
00114     if (!AV_RN32(wc->extra))
00115         return 0;
00116     //parse flags
00117     bpp = ((wc->flags & 3) + 1) << 3;
00118     chan = 1 + !(wc->flags & WV_MONO);
00119     chmask = wc->flags & WV_MONO ? AV_CH_LAYOUT_MONO : AV_CH_LAYOUT_STEREO;
00120     rate = wv_rates[(wc->flags >> 23) & 0xF];
00121     wc->multichannel = !!((wc->flags & WV_SINGLE_BLOCK) != WV_SINGLE_BLOCK);
00122     if(wc->multichannel){
00123         chan = wc->chan;
00124         chmask = wc->chmask;
00125     }
00126     if((rate == -1 || !chan) && !wc->block_parsed){
00127         int64_t block_end = avio_tell(pb) + wc->blksize - 24;
00128         if(!pb->seekable){
00129             av_log(ctx, AV_LOG_ERROR, "Cannot determine additional parameters\n");
00130             return -1;
00131         }
00132         while(avio_tell(pb) < block_end){
00133             int id, size;
00134             id = avio_r8(pb);
00135             size = (id & 0x80) ? avio_rl24(pb) : avio_r8(pb);
00136             size <<= 1;
00137             if(id&0x40)
00138                 size--;
00139             switch(id&0x3F){
00140             case 0xD:
00141                 if(size <= 1){
00142                     av_log(ctx, AV_LOG_ERROR, "Insufficient channel information\n");
00143                     return -1;
00144                 }
00145                 chan = avio_r8(pb);
00146                 switch(size - 2){
00147                 case 0:
00148                     chmask = avio_r8(pb);
00149                     break;
00150                 case 1:
00151                     chmask = avio_rl16(pb);
00152                     break;
00153                 case 2:
00154                     chmask = avio_rl24(pb);
00155                     break;
00156                 case 3:
00157                     chmask = avio_rl32(pb);
00158                     break;
00159                 case 5:
00160                     avio_skip(pb, 1);
00161                     chan |= (avio_r8(pb) & 0xF) << 8;
00162                     chmask = avio_rl24(pb);
00163                     break;
00164                 default:
00165                     av_log(ctx, AV_LOG_ERROR, "Invalid channel info size %d\n", size);
00166                     return -1;
00167                 }
00168                 break;
00169             case 0x27:
00170                 rate = avio_rl24(pb);
00171                 break;
00172             default:
00173                 avio_skip(pb, size);
00174             }
00175             if(id&0x40)
00176                 avio_skip(pb, 1);
00177         }
00178         if(rate == -1){
00179             av_log(ctx, AV_LOG_ERROR, "Cannot determine custom sampling rate\n");
00180             return -1;
00181         }
00182         avio_seek(pb, block_end - wc->blksize + 24, SEEK_SET);
00183     }
00184     if(!wc->bpp) wc->bpp = bpp;
00185     if(!wc->chan) wc->chan = chan;
00186     if(!wc->chmask) wc->chmask = chmask;
00187     if(!wc->rate) wc->rate = rate;
00188 
00189     if(wc->flags && bpp != wc->bpp){
00190         av_log(ctx, AV_LOG_ERROR, "Bits per sample differ, this block: %i, header block: %i\n", bpp, wc->bpp);
00191         return -1;
00192     }
00193     if(wc->flags && !wc->multichannel && chan != wc->chan){
00194         av_log(ctx, AV_LOG_ERROR, "Channels differ, this block: %i, header block: %i\n", chan, wc->chan);
00195         return -1;
00196     }
00197     if(wc->flags && rate != -1 && rate != wc->rate){
00198         av_log(ctx, AV_LOG_ERROR, "Sampling rate differ, this block: %i, header block: %i\n", rate, wc->rate);
00199         return -1;
00200     }
00201     wc->blksize = size - 24;
00202     return 0;
00203 }
00204 
00205 static int wv_read_header(AVFormatContext *s,
00206                           AVFormatParameters *ap)
00207 {
00208     AVIOContext *pb = s->pb;
00209     WVContext *wc = s->priv_data;
00210     AVStream *st;
00211 
00212     wc->block_parsed = 0;
00213     for(;;){
00214         if(wv_read_block_header(s, pb, 0) < 0)
00215             return -1;
00216         if(!AV_RN32(wc->extra))
00217             avio_skip(pb, wc->blksize - 24);
00218         else
00219             break;
00220     }
00221 
00222     /* now we are ready: build format streams */
00223     st = av_new_stream(s, 0);
00224     if (!st)
00225         return -1;
00226     st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
00227     st->codec->codec_id = CODEC_ID_WAVPACK;
00228     st->codec->channels = wc->chan;
00229     st->codec->channel_layout = wc->chmask;
00230     st->codec->sample_rate = wc->rate;
00231     st->codec->bits_per_coded_sample = wc->bpp;
00232     av_set_pts_info(st, 64, 1, wc->rate);
00233     st->start_time = 0;
00234     st->duration = wc->samples;
00235 
00236     if(s->pb->seekable) {
00237         int64_t cur = avio_tell(s->pb);
00238         ff_ape_parse_tag(s);
00239         if(!av_dict_get(s->metadata, "", NULL, AV_DICT_IGNORE_SUFFIX))
00240             ff_id3v1_read(s);
00241         avio_seek(s->pb, cur, SEEK_SET);
00242     }
00243 
00244     return 0;
00245 }
00246 
00247 static int wv_read_packet(AVFormatContext *s,
00248                           AVPacket *pkt)
00249 {
00250     WVContext *wc = s->priv_data;
00251     int ret;
00252     int size, ver, off;
00253 
00254     if (s->pb->eof_reached)
00255         return AVERROR(EIO);
00256     if(wc->block_parsed){
00257         if(wv_read_block_header(s, s->pb, 0) < 0)
00258             return -1;
00259     }
00260 
00261     off = wc->multichannel ? 4 : 0;
00262     if(av_new_packet(pkt, wc->blksize + WV_EXTRA_SIZE + off) < 0)
00263         return AVERROR(ENOMEM);
00264     if(wc->multichannel)
00265         AV_WL32(pkt->data, wc->blksize + WV_EXTRA_SIZE + 12);
00266     memcpy(pkt->data + off, wc->extra, WV_EXTRA_SIZE);
00267     ret = avio_read(s->pb, pkt->data + WV_EXTRA_SIZE + off, wc->blksize);
00268     if(ret != wc->blksize){
00269         av_free_packet(pkt);
00270         return AVERROR(EIO);
00271     }
00272     while(!(wc->flags & WV_END_BLOCK)){
00273         if(avio_rl32(s->pb) != MKTAG('w', 'v', 'p', 'k')){
00274             av_free_packet(pkt);
00275             return -1;
00276         }
00277         if((ret = av_append_packet(s->pb, pkt, 4)) < 0){
00278             av_free_packet(pkt);
00279             return ret;
00280         }
00281         size = AV_RL32(pkt->data + pkt->size - 4);
00282         if(size < 24 || size > WV_BLOCK_LIMIT){
00283             av_free_packet(pkt);
00284             av_log(s, AV_LOG_ERROR, "Incorrect block size %d\n", size);
00285             return -1;
00286         }
00287         wc->blksize = size;
00288         ver = avio_rl16(s->pb);
00289         if(ver < 0x402 || ver > 0x410){
00290             av_free_packet(pkt);
00291             av_log(s, AV_LOG_ERROR, "Unsupported version %03X\n", ver);
00292             return -1;
00293         }
00294         avio_r8(s->pb); // track no
00295         avio_r8(s->pb); // track sub index
00296         wc->samples = avio_rl32(s->pb); // total samples in file
00297         wc->soff = avio_rl32(s->pb); // offset in samples of current block
00298         if((ret = av_append_packet(s->pb, pkt, WV_EXTRA_SIZE)) < 0){
00299             av_free_packet(pkt);
00300             return ret;
00301         }
00302         memcpy(wc->extra, pkt->data + pkt->size - WV_EXTRA_SIZE, WV_EXTRA_SIZE);
00303 
00304         if(wv_read_block_header(s, s->pb, 1) < 0){
00305             av_free_packet(pkt);
00306             return -1;
00307         }
00308         ret = av_append_packet(s->pb, pkt, wc->blksize);
00309         if(ret < 0){
00310             av_free_packet(pkt);
00311             return ret;
00312         }
00313     }
00314     pkt->stream_index = 0;
00315     wc->block_parsed = 1;
00316     pkt->pts = wc->soff;
00317     av_add_index_entry(s->streams[0], wc->pos, pkt->pts, 0, 0, AVINDEX_KEYFRAME);
00318     return 0;
00319 }
00320 
00321 static int wv_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
00322 {
00323     AVStream *st = s->streams[stream_index];
00324     WVContext *wc = s->priv_data;
00325     AVPacket pkt1, *pkt = &pkt1;
00326     int ret;
00327     int index = av_index_search_timestamp(st, timestamp, flags);
00328     int64_t pos, pts;
00329 
00330     /* if found, seek there */
00331     if (index >= 0){
00332         wc->block_parsed = 1;
00333         avio_seek(s->pb, st->index_entries[index].pos, SEEK_SET);
00334         return 0;
00335     }
00336     /* if timestamp is out of bounds, return error */
00337     if(timestamp < 0 || timestamp >= s->duration)
00338         return -1;
00339 
00340     pos = avio_tell(s->pb);
00341     do{
00342         ret = av_read_frame(s, pkt);
00343         if (ret < 0){
00344             avio_seek(s->pb, pos, SEEK_SET);
00345             return -1;
00346         }
00347         pts = pkt->pts;
00348         av_free_packet(pkt);
00349     }while(pts < timestamp);
00350     return 0;
00351 }
00352 
00353 AVInputFormat ff_wv_demuxer = {
00354     "wv",
00355     NULL_IF_CONFIG_SMALL("WavPack"),
00356     sizeof(WVContext),
00357     wv_probe,
00358     wv_read_header,
00359     wv_read_packet,
00360     NULL,
00361     wv_read_seek,
00362 };