Libav 0.7.1
libavformat/aiffdec.c
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00001 /*
00002  * AIFF/AIFF-C demuxer
00003  * Copyright (c) 2006  Patrick Guimond
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/intfloat_readwrite.h"
00023 #include "libavutil/dict.h"
00024 #include "avformat.h"
00025 #include "pcm.h"
00026 #include "aiff.h"
00027 
00028 #define AIFF                    0
00029 #define AIFF_C_VERSION1         0xA2805140
00030 
00031 typedef struct {
00032     int64_t data_end;
00033 } AIFFInputContext;
00034 
00035 static enum CodecID aiff_codec_get_id(int bps)
00036 {
00037     if (bps <= 8)
00038         return CODEC_ID_PCM_S8;
00039     if (bps <= 16)
00040         return CODEC_ID_PCM_S16BE;
00041     if (bps <= 24)
00042         return CODEC_ID_PCM_S24BE;
00043     if (bps <= 32)
00044         return CODEC_ID_PCM_S32BE;
00045 
00046     /* bigger than 32 isn't allowed  */
00047     return CODEC_ID_NONE;
00048 }
00049 
00050 /* returns the size of the found tag */
00051 static int get_tag(AVIOContext *pb, uint32_t * tag)
00052 {
00053     int size;
00054 
00055     if (pb->eof_reached)
00056         return AVERROR(EIO);
00057 
00058     *tag = avio_rl32(pb);
00059     size = avio_rb32(pb);
00060 
00061     if (size < 0)
00062         size = 0x7fffffff;
00063 
00064     return size;
00065 }
00066 
00067 /* Metadata string read */
00068 static void get_meta(AVFormatContext *s, const char *key, int size)
00069 {
00070     uint8_t *str = av_malloc(size+1);
00071     int res;
00072 
00073     if (!str) {
00074         avio_skip(s->pb, size);
00075         return;
00076     }
00077 
00078     res = avio_read(s->pb, str, size);
00079     if (res < 0)
00080         return;
00081 
00082     str[res] = 0;
00083     av_dict_set(&s->metadata, key, str, AV_DICT_DONT_STRDUP_VAL);
00084 }
00085 
00086 /* Returns the number of sound data frames or negative on error */
00087 static unsigned int get_aiff_header(AVIOContext *pb, AVCodecContext *codec,
00088                              int size, unsigned version)
00089 {
00090     AVExtFloat ext;
00091     double sample_rate;
00092     unsigned int num_frames;
00093 
00094     if (size & 1)
00095         size++;
00096     codec->codec_type = AVMEDIA_TYPE_AUDIO;
00097     codec->channels = avio_rb16(pb);
00098     num_frames = avio_rb32(pb);
00099     codec->bits_per_coded_sample = avio_rb16(pb);
00100 
00101     avio_read(pb, (uint8_t*)&ext, sizeof(ext));/* Sample rate is in */
00102     sample_rate = av_ext2dbl(ext);          /* 80 bits BE IEEE extended float */
00103     codec->sample_rate = sample_rate;
00104     size -= 18;
00105 
00106     /* Got an AIFF-C? */
00107     if (version == AIFF_C_VERSION1) {
00108         codec->codec_tag = avio_rl32(pb);
00109         codec->codec_id  = ff_codec_get_id(ff_codec_aiff_tags, codec->codec_tag);
00110 
00111         switch (codec->codec_id) {
00112         case CODEC_ID_PCM_S16BE:
00113             codec->codec_id = aiff_codec_get_id(codec->bits_per_coded_sample);
00114             codec->bits_per_coded_sample = av_get_bits_per_sample(codec->codec_id);
00115             break;
00116         case CODEC_ID_ADPCM_IMA_QT:
00117             codec->block_align = 34*codec->channels;
00118             codec->frame_size = 64;
00119             break;
00120         case CODEC_ID_MACE3:
00121             codec->block_align = 2*codec->channels;
00122             codec->frame_size = 6;
00123             break;
00124         case CODEC_ID_MACE6:
00125             codec->block_align = 1*codec->channels;
00126             codec->frame_size = 6;
00127             break;
00128         case CODEC_ID_GSM:
00129             codec->block_align = 33;
00130             codec->frame_size = 160;
00131             break;
00132         case CODEC_ID_QCELP:
00133             codec->block_align = 35;
00134             codec->frame_size= 160;
00135             break;
00136         default:
00137             break;
00138         }
00139         size -= 4;
00140     } else {
00141         /* Need the codec type */
00142         codec->codec_id = aiff_codec_get_id(codec->bits_per_coded_sample);
00143         codec->bits_per_coded_sample = av_get_bits_per_sample(codec->codec_id);
00144     }
00145 
00146     /* Block align needs to be computed in all cases, as the definition
00147      * is specific to applications -> here we use the WAVE format definition */
00148     if (!codec->block_align)
00149         codec->block_align = (codec->bits_per_coded_sample * codec->channels) >> 3;
00150 
00151     codec->bit_rate = (codec->frame_size ? codec->sample_rate/codec->frame_size :
00152                        codec->sample_rate) * (codec->block_align << 3);
00153 
00154     /* Chunk is over */
00155     if (size)
00156         avio_skip(pb, size);
00157 
00158     return num_frames;
00159 }
00160 
00161 static int aiff_probe(AVProbeData *p)
00162 {
00163     /* check file header */
00164     if (p->buf[0] == 'F' && p->buf[1] == 'O' &&
00165         p->buf[2] == 'R' && p->buf[3] == 'M' &&
00166         p->buf[8] == 'A' && p->buf[9] == 'I' &&
00167         p->buf[10] == 'F' && (p->buf[11] == 'F' || p->buf[11] == 'C'))
00168         return AVPROBE_SCORE_MAX;
00169     else
00170         return 0;
00171 }
00172 
00173 /* aiff input */
00174 static int aiff_read_header(AVFormatContext *s,
00175                             AVFormatParameters *ap)
00176 {
00177     int size, filesize;
00178     int64_t offset = 0;
00179     uint32_t tag;
00180     unsigned version = AIFF_C_VERSION1;
00181     AVIOContext *pb = s->pb;
00182     AVStream * st;
00183     AIFFInputContext *aiff = s->priv_data;
00184 
00185     /* check FORM header */
00186     filesize = get_tag(pb, &tag);
00187     if (filesize < 0 || tag != MKTAG('F', 'O', 'R', 'M'))
00188         return AVERROR_INVALIDDATA;
00189 
00190     /* AIFF data type */
00191     tag = avio_rl32(pb);
00192     if (tag == MKTAG('A', 'I', 'F', 'F'))       /* Got an AIFF file */
00193         version = AIFF;
00194     else if (tag != MKTAG('A', 'I', 'F', 'C'))  /* An AIFF-C file then */
00195         return AVERROR_INVALIDDATA;
00196 
00197     filesize -= 4;
00198 
00199     st = av_new_stream(s, 0);
00200     if (!st)
00201         return AVERROR(ENOMEM);
00202 
00203     while (filesize > 0) {
00204         /* parse different chunks */
00205         size = get_tag(pb, &tag);
00206         if (size < 0)
00207             return size;
00208 
00209         filesize -= size + 8;
00210 
00211         switch (tag) {
00212         case MKTAG('C', 'O', 'M', 'M'):     /* Common chunk */
00213             /* Then for the complete header info */
00214             st->nb_frames = get_aiff_header(pb, st->codec, size, version);
00215             if (st->nb_frames < 0)
00216                 return st->nb_frames;
00217             if (offset > 0) // COMM is after SSND
00218                 goto got_sound;
00219             break;
00220         case MKTAG('F', 'V', 'E', 'R'):     /* Version chunk */
00221             version = avio_rb32(pb);
00222             break;
00223         case MKTAG('N', 'A', 'M', 'E'):     /* Sample name chunk */
00224             get_meta(s, "title"    , size);
00225             break;
00226         case MKTAG('A', 'U', 'T', 'H'):     /* Author chunk */
00227             get_meta(s, "author"   , size);
00228             break;
00229         case MKTAG('(', 'c', ')', ' '):     /* Copyright chunk */
00230             get_meta(s, "copyright", size);
00231             break;
00232         case MKTAG('A', 'N', 'N', 'O'):     /* Annotation chunk */
00233             get_meta(s, "comment"  , size);
00234             break;
00235         case MKTAG('S', 'S', 'N', 'D'):     /* Sampled sound chunk */
00236             aiff->data_end = avio_tell(pb) + size;
00237             offset = avio_rb32(pb);      /* Offset of sound data */
00238             avio_rb32(pb);               /* BlockSize... don't care */
00239             offset += avio_tell(pb);    /* Compute absolute data offset */
00240             if (st->codec->block_align)    /* Assume COMM already parsed */
00241                 goto got_sound;
00242             if (!pb->seekable) {
00243                 av_log(s, AV_LOG_ERROR, "file is not seekable\n");
00244                 return -1;
00245             }
00246             avio_skip(pb, size - 8);
00247             break;
00248         case MKTAG('w', 'a', 'v', 'e'):
00249             if ((uint64_t)size > (1<<30))
00250                 return -1;
00251             st->codec->extradata = av_mallocz(size + FF_INPUT_BUFFER_PADDING_SIZE);
00252             if (!st->codec->extradata)
00253                 return AVERROR(ENOMEM);
00254             st->codec->extradata_size = size;
00255             avio_read(pb, st->codec->extradata, size);
00256             break;
00257         default: /* Jump */
00258             if (size & 1)   /* Always even aligned */
00259                 size++;
00260             avio_skip(pb, size);
00261         }
00262     }
00263 
00264     if (!st->codec->block_align) {
00265         av_log(s, AV_LOG_ERROR, "could not find COMM tag\n");
00266         return -1;
00267     }
00268 
00269 got_sound:
00270     /* Now positioned, get the sound data start and end */
00271     if (st->nb_frames)
00272         s->file_size = st->nb_frames * st->codec->block_align;
00273 
00274     av_set_pts_info(st, 64, 1, st->codec->sample_rate);
00275     st->start_time = 0;
00276     st->duration = st->codec->frame_size ?
00277         st->nb_frames * st->codec->frame_size : st->nb_frames;
00278 
00279     /* Position the stream at the first block */
00280     avio_seek(pb, offset, SEEK_SET);
00281 
00282     return 0;
00283 }
00284 
00285 #define MAX_SIZE 4096
00286 
00287 static int aiff_read_packet(AVFormatContext *s,
00288                             AVPacket *pkt)
00289 {
00290     AVStream *st = s->streams[0];
00291     AIFFInputContext *aiff = s->priv_data;
00292     int64_t max_size;
00293     int res, size;
00294 
00295     /* calculate size of remaining data */
00296     max_size = aiff->data_end - avio_tell(s->pb);
00297     if (max_size <= 0)
00298         return AVERROR_EOF;
00299 
00300     /* Now for that packet */
00301     if (st->codec->block_align >= 33) // GSM, QCLP, IMA4
00302         size = st->codec->block_align;
00303     else
00304         size = (MAX_SIZE / st->codec->block_align) * st->codec->block_align;
00305     size = FFMIN(max_size, size);
00306     res = av_get_packet(s->pb, pkt, size);
00307     if (res < 0)
00308         return res;
00309 
00310     /* Only one stream in an AIFF file */
00311     pkt->stream_index = 0;
00312     return 0;
00313 }
00314 
00315 AVInputFormat ff_aiff_demuxer = {
00316     "aiff",
00317     NULL_IF_CONFIG_SMALL("Audio IFF"),
00318     sizeof(AIFFInputContext),
00319     aiff_probe,
00320     aiff_read_header,
00321     aiff_read_packet,
00322     NULL,
00323     pcm_read_seek,
00324     .codec_tag= (const AVCodecTag* const []){ff_codec_aiff_tags, 0},
00325 };