FFmpeg: libavformat/wv.c Source File

00001 /*
00002  * WavPack demuxer
00003  * Copyright (c) 2006 Konstantin Shishkov
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 "libavutil/intreadwrite.h"
00023 #include "avformat.h"
00024 #include "apetag.h"
00025 #include "id3v1.h"
00026 
00027 // specs say that maximum block size is 1Mb
00028 #define WV_BLOCK_LIMIT 1047576
00029 
00030 #define WV_EXTRA_SIZE 12
00031 
00032 enum WV_FLAGS{
00033     WV_MONO   = 0x0004,
00034     WV_HYBRID = 0x0008,
00035     WV_JOINT  = 0x0010,
00036     WV_CROSSD = 0x0020,
00037     WV_HSHAPE = 0x0040,
00038     WV_FLOAT  = 0x0080,
00039     WV_INT32  = 0x0100,
00040     WV_HBR    = 0x0200,
00041     WV_HBAL   = 0x0400,
00042     WV_MCINIT = 0x0800,
00043     WV_MCEND  = 0x1000,
00044 };
00045 
00046 static const int wv_rates[16] = {
00047      6000,  8000,  9600, 11025, 12000, 16000, 22050, 24000,
00048     32000, 44100, 48000, 64000, 88200, 96000, 192000, -1
00049 };
00050 
00051 typedef struct{
00052     uint32_t blksize, flags;
00053     int rate, chan, bpp;
00054     uint32_t samples, soff;
00055     int block_parsed;
00056     uint8_t extra[WV_EXTRA_SIZE];
00057     int64_t pos;
00058 }WVContext;
00059 
00060 static int wv_probe(AVProbeData *p)
00061 {
00062     /* check file header */
00063     if (p->buf_size <= 32)
00064         return 0;
00065     if (p->buf[0] == 'w' && p->buf[1] == 'v' &&
00066         p->buf[2] == 'p' && p->buf[3] == 'k')
00067         return AVPROBE_SCORE_MAX;
00068     else
00069         return 0;
00070 }
00071 
00072 static int wv_read_block_header(AVFormatContext *ctx, ByteIOContext *pb)
00073 {
00074     WVContext *wc = ctx->priv_data;
00075     uint32_t tag, ver;
00076     int size;
00077     int rate, bpp, chan;
00078 
00079     wc->pos = url_ftell(pb);
00080     tag = get_le32(pb);
00081     if (tag != MKTAG('w', 'v', 'p', 'k'))
00082         return -1;
00083     size = get_le32(pb);
00084     if(size < 24 || size > WV_BLOCK_LIMIT){
00085         av_log(ctx, AV_LOG_ERROR, "Incorrect block size %i\n", size);
00086         return -1;
00087     }
00088     wc->blksize = size;
00089     ver = get_le16(pb);
00090     if(ver < 0x402 || ver > 0x410){
00091         av_log(ctx, AV_LOG_ERROR, "Unsupported version %03X\n", ver);
00092         return -1;
00093     }
00094     get_byte(pb); // track no
00095     get_byte(pb); // track sub index
00096     wc->samples = get_le32(pb); // total samples in file
00097     wc->soff = get_le32(pb); // offset in samples of current block
00098     get_buffer(pb, wc->extra, WV_EXTRA_SIZE);
00099     wc->flags = AV_RL32(wc->extra + 4);
00100     //parse flags
00101     bpp = ((wc->flags & 3) + 1) << 3;
00102     chan = 1 + !(wc->flags & WV_MONO);
00103     rate = wv_rates[(wc->flags >> 23) & 0xF];
00104     if((wc->flags & 0x1800) != 0x1800){
00105         av_log(ctx, AV_LOG_ERROR, "Multichannel WavPack is not supported yet.\n");
00106         return -1;
00107     }
00108     if(rate == -1 && !wc->block_parsed){
00109         int64_t block_end = url_ftell(pb) + wc->blksize - 24;
00110         if(url_is_streamed(pb)){
00111             av_log(ctx, AV_LOG_ERROR, "Cannot determine custom sampling rate\n");
00112             return -1;
00113         }
00114         while(url_ftell(pb) < block_end){
00115             int id, size;
00116             id = get_byte(pb);
00117             size = (id & 0x80) ? get_le24(pb) : get_byte(pb);
00118             size <<= 1;
00119             if(id&0x40)
00120                 size--;
00121             if((id&0x3F) == 0x27){
00122                 rate = get_le24(pb);
00123                 break;
00124             }else{
00125                 url_fskip(pb, size);
00126             }
00127         }
00128         if(rate == -1){
00129             av_log(ctx, AV_LOG_ERROR, "Cannot determine custom sampling rate\n");
00130             return -1;
00131         }
00132         url_fseek(pb, block_end - wc->blksize + 24, SEEK_SET);
00133     }
00134     if(!wc->bpp) wc->bpp = bpp;
00135     if(!wc->chan) wc->chan = chan;
00136     if(!wc->rate) wc->rate = rate;
00137 
00138     if(wc->flags && bpp != wc->bpp){
00139         av_log(ctx, AV_LOG_ERROR, "Bits per sample differ, this block: %i, header block: %i\n", bpp, wc->bpp);
00140         return -1;
00141     }
00142     if(wc->flags && chan != wc->chan){
00143         av_log(ctx, AV_LOG_ERROR, "Channels differ, this block: %i, header block: %i\n", chan, wc->chan);
00144         return -1;
00145     }
00146     if(wc->flags && rate != -1 && rate != wc->rate){
00147         av_log(ctx, AV_LOG_ERROR, "Sampling rate differ, this block: %i, header block: %i\n", rate, wc->rate);
00148         return -1;
00149     }
00150     wc->blksize = size - 24;
00151     return 0;
00152 }
00153 
00154 static int wv_read_header(AVFormatContext *s,
00155                           AVFormatParameters *ap)
00156 {
00157     ByteIOContext *pb = s->pb;
00158     WVContext *wc = s->priv_data;
00159     AVStream *st;
00160 
00161     wc->block_parsed = 0;
00162     if(wv_read_block_header(s, pb) < 0)
00163         return -1;
00164 
00165     /* now we are ready: build format streams */
00166     st = av_new_stream(s, 0);
00167     if (!st)
00168         return -1;
00169     st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
00170     st->codec->codec_id = CODEC_ID_WAVPACK;
00171     st->codec->channels = wc->chan;
00172     st->codec->sample_rate = wc->rate;
00173     st->codec->bits_per_coded_sample = wc->bpp;
00174     av_set_pts_info(st, 64, 1, wc->rate);
00175     st->start_time = 0;
00176     st->duration = wc->samples;
00177 
00178     if(!url_is_streamed(s->pb)) {
00179         int64_t cur = url_ftell(s->pb);
00180         ff_ape_parse_tag(s);
00181         if(!av_metadata_get(s->metadata, "", NULL, AV_METADATA_IGNORE_SUFFIX))
00182             ff_id3v1_read(s);
00183         url_fseek(s->pb, cur, SEEK_SET);
00184     }
00185 
00186     return 0;
00187 }
00188 
00189 static int wv_read_packet(AVFormatContext *s,
00190                           AVPacket *pkt)
00191 {
00192     WVContext *wc = s->priv_data;
00193     int ret;
00194 
00195     if (url_feof(s->pb))
00196         return AVERROR(EIO);
00197     if(wc->block_parsed){
00198         if(wv_read_block_header(s, s->pb) < 0)
00199             return -1;
00200     }
00201 
00202     if(av_new_packet(pkt, wc->blksize + WV_EXTRA_SIZE) < 0)
00203         return AVERROR(ENOMEM);
00204     memcpy(pkt->data, wc->extra, WV_EXTRA_SIZE);
00205     ret = get_buffer(s->pb, pkt->data + WV_EXTRA_SIZE, wc->blksize);
00206     if(ret != wc->blksize){
00207         av_free_packet(pkt);
00208         return AVERROR(EIO);
00209     }
00210     pkt->stream_index = 0;
00211     wc->block_parsed = 1;
00212     pkt->size = ret + WV_EXTRA_SIZE;
00213     pkt->pts = wc->soff;
00214     av_add_index_entry(s->streams[0], wc->pos, pkt->pts, 0, 0, AVINDEX_KEYFRAME);
00215     return 0;
00216 }
00217 
00218 static int wv_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
00219 {
00220     AVStream *st = s->streams[stream_index];
00221     WVContext *wc = s->priv_data;
00222     AVPacket pkt1, *pkt = &pkt1;
00223     int ret;
00224     int index = av_index_search_timestamp(st, timestamp, flags);
00225     int64_t pos, pts;
00226 
00227     /* if found, seek there */
00228     if (index >= 0){
00229         wc->block_parsed = 1;
00230         url_fseek(s->pb, st->index_entries[index].pos, SEEK_SET);
00231         return 0;
00232     }
00233     /* if timestamp is out of bounds, return error */
00234     if(timestamp < 0 || timestamp >= s->duration)
00235         return -1;
00236 
00237     pos = url_ftell(s->pb);
00238     do{
00239         ret = av_read_frame(s, pkt);
00240         if (ret < 0){
00241             url_fseek(s->pb, pos, SEEK_SET);
00242             return -1;
00243         }
00244         pts = pkt->pts;
00245         av_free_packet(pkt);
00246     }while(pts < timestamp);
00247     return 0;
00248 }
00249 
00250 AVInputFormat wv_demuxer = {
00251     "wv",
00252     NULL_IF_CONFIG_SMALL("WavPack"),
00253     sizeof(WVContext),
00254     wv_probe,
00255     wv_read_header,
00256     wv_read_packet,
00257     NULL,
00258     wv_read_seek,
00259 };