FFmpeg: libavformat/aiffdec.c Source File

00001 /*
00002  * AIFF/AIFF-C demuxer
00003  * Copyright (c) 2006  Patrick Guimond
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/mathematics.h"
00023 #include "libavutil/dict.h"
00024 #include "avformat.h"
00025 #include "internal.h"
00026 #include "pcm.h"
00027 #include "aiff.h"
00028 #include "isom.h"
00029 
00030 #define AIFF                    0
00031 #define AIFF_C_VERSION1         0xA2805140
00032 
00033 typedef struct {
00034     int64_t data_end;
00035 } AIFFInputContext;
00036 
00037 static enum CodecID aiff_codec_get_id(int bps)
00038 {
00039     if (bps <= 8)
00040         return CODEC_ID_PCM_S8;
00041     if (bps <= 16)
00042         return CODEC_ID_PCM_S16BE;
00043     if (bps <= 24)
00044         return CODEC_ID_PCM_S24BE;
00045     if (bps <= 32)
00046         return CODEC_ID_PCM_S32BE;
00047 
00048     /* bigger than 32 isn't allowed  */
00049     return CODEC_ID_NONE;
00050 }
00051 
00052 /* returns the size of the found tag */
00053 static int get_tag(AVIOContext *pb, uint32_t * tag)
00054 {
00055     int size;
00056 
00057     if (url_feof(pb))
00058         return AVERROR(EIO);
00059 
00060     *tag = avio_rl32(pb);
00061     size = avio_rb32(pb);
00062 
00063     if (size < 0)
00064         size = 0x7fffffff;
00065 
00066     return size;
00067 }
00068 
00069 /* Metadata string read */
00070 static void get_meta(AVFormatContext *s, const char *key, int size)
00071 {
00072     uint8_t *str = av_malloc(size+1);
00073 
00074     if (str) {
00075         int res = avio_read(s->pb, str, size);
00076         if (res < 0){
00077             av_free(str);
00078             return;
00079         }
00080         size += (size&1)-res;
00081         str[res] = 0;
00082         av_dict_set(&s->metadata, key, str, AV_METADATA_DONT_STRDUP_VAL);
00083     }else
00084         size+= size&1;
00085 
00086     avio_skip(s->pb, size);
00087 }
00088 
00089 /* Returns the number of sound data frames or negative on error */
00090 static unsigned int get_aiff_header(AVIOContext *pb, AVCodecContext *codec,
00091                              int size, unsigned version)
00092 {
00093     int exp;
00094     uint64_t val;
00095     double sample_rate;
00096     unsigned int num_frames;
00097 
00098     if (size & 1)
00099         size++;
00100     codec->codec_type = AVMEDIA_TYPE_AUDIO;
00101     codec->channels = avio_rb16(pb);
00102     num_frames = avio_rb32(pb);
00103     codec->bits_per_coded_sample = avio_rb16(pb);
00104 
00105     exp = avio_rb16(pb);
00106     val = avio_rb64(pb);
00107     sample_rate = ldexp(val, exp - 16383 - 63);
00108     codec->sample_rate = sample_rate;
00109     size -= 18;
00110 
00111     /* Got an AIFF-C? */
00112     if (version == AIFF_C_VERSION1) {
00113         codec->codec_tag = avio_rl32(pb);
00114         codec->codec_id  = ff_codec_get_id(ff_codec_aiff_tags, codec->codec_tag);
00115 
00116         switch (codec->codec_id) {
00117         case CODEC_ID_PCM_S16BE:
00118             codec->codec_id = aiff_codec_get_id(codec->bits_per_coded_sample);
00119             codec->bits_per_coded_sample = av_get_bits_per_sample(codec->codec_id);
00120             break;
00121         case CODEC_ID_ADPCM_IMA_QT:
00122             codec->block_align = 34*codec->channels;
00123             codec->frame_size = 64;
00124             break;
00125         case CODEC_ID_MACE3:
00126             codec->block_align = 2*codec->channels;
00127             codec->frame_size = 6;
00128             break;
00129         case CODEC_ID_MACE6:
00130             codec->block_align = 1*codec->channels;
00131             codec->frame_size = 6;
00132             break;
00133         case CODEC_ID_GSM:
00134             codec->block_align = 33;
00135             codec->frame_size = 160;
00136             break;
00137         case CODEC_ID_QCELP:
00138             codec->block_align = 35;
00139             codec->frame_size= 160;
00140             break;
00141         default:
00142             break;
00143         }
00144         size -= 4;
00145     } else {
00146         /* Need the codec type */
00147         codec->codec_id = aiff_codec_get_id(codec->bits_per_coded_sample);
00148         codec->bits_per_coded_sample = av_get_bits_per_sample(codec->codec_id);
00149     }
00150 
00151     /* Block align needs to be computed in all cases, as the definition
00152      * is specific to applications -> here we use the WAVE format definition */
00153     if (!codec->block_align)
00154         codec->block_align = (codec->bits_per_coded_sample * codec->channels) >> 3;
00155 
00156     codec->bit_rate = (codec->frame_size ? codec->sample_rate/codec->frame_size :
00157                        codec->sample_rate) * (codec->block_align << 3);
00158 
00159     /* Chunk is over */
00160     if (size)
00161         avio_skip(pb, size);
00162 
00163     return num_frames;
00164 }
00165 
00166 static int aiff_probe(AVProbeData *p)
00167 {
00168     /* check file header */
00169     if (p->buf[0] == 'F' && p->buf[1] == 'O' &&
00170         p->buf[2] == 'R' && p->buf[3] == 'M' &&
00171         p->buf[8] == 'A' && p->buf[9] == 'I' &&
00172         p->buf[10] == 'F' && (p->buf[11] == 'F' || p->buf[11] == 'C'))
00173         return AVPROBE_SCORE_MAX;
00174     else
00175         return 0;
00176 }
00177 
00178 /* aiff input */
00179 static int aiff_read_header(AVFormatContext *s,
00180                             AVFormatParameters *ap)
00181 {
00182     int size, filesize;
00183     int64_t offset = 0;
00184     uint32_t tag;
00185     unsigned version = AIFF_C_VERSION1;
00186     AVIOContext *pb = s->pb;
00187     AVStream * st;
00188     AIFFInputContext *aiff = s->priv_data;
00189 
00190     /* check FORM header */
00191     filesize = get_tag(pb, &tag);
00192     if (filesize < 0 || tag != MKTAG('F', 'O', 'R', 'M'))
00193         return AVERROR_INVALIDDATA;
00194 
00195     /* AIFF data type */
00196     tag = avio_rl32(pb);
00197     if (tag == MKTAG('A', 'I', 'F', 'F'))       /* Got an AIFF file */
00198         version = AIFF;
00199     else if (tag != MKTAG('A', 'I', 'F', 'C'))  /* An AIFF-C file then */
00200         return AVERROR_INVALIDDATA;
00201 
00202     filesize -= 4;
00203 
00204     st = avformat_new_stream(s, NULL);
00205     if (!st)
00206         return AVERROR(ENOMEM);
00207 
00208     while (filesize > 0) {
00209         /* parse different chunks */
00210         size = get_tag(pb, &tag);
00211         if (size < 0)
00212             return size;
00213 
00214         filesize -= size + 8;
00215 
00216         switch (tag) {
00217         case MKTAG('C', 'O', 'M', 'M'):     /* Common chunk */
00218             /* Then for the complete header info */
00219             st->nb_frames = get_aiff_header(pb, st->codec, size, version);
00220             if (st->nb_frames < 0)
00221                 return st->nb_frames;
00222             if (offset > 0) // COMM is after SSND
00223                 goto got_sound;
00224             break;
00225         case MKTAG('F', 'V', 'E', 'R'):     /* Version chunk */
00226             version = avio_rb32(pb);
00227             break;
00228         case MKTAG('N', 'A', 'M', 'E'):     /* Sample name chunk */
00229             get_meta(s, "title"    , size);
00230             break;
00231         case MKTAG('A', 'U', 'T', 'H'):     /* Author chunk */
00232             get_meta(s, "author"   , size);
00233             break;
00234         case MKTAG('(', 'c', ')', ' '):     /* Copyright chunk */
00235             get_meta(s, "copyright", size);
00236             break;
00237         case MKTAG('A', 'N', 'N', 'O'):     /* Annotation chunk */
00238             get_meta(s, "comment"  , size);
00239             break;
00240         case MKTAG('S', 'S', 'N', 'D'):     /* Sampled sound chunk */
00241             aiff->data_end = avio_tell(pb) + size;
00242             offset = avio_rb32(pb);      /* Offset of sound data */
00243             avio_rb32(pb);               /* BlockSize... don't care */
00244             offset += avio_tell(pb);    /* Compute absolute data offset */
00245             if (st->codec->block_align)    /* Assume COMM already parsed */
00246                 goto got_sound;
00247             if (!pb->seekable) {
00248                 av_log(s, AV_LOG_ERROR, "file is not seekable\n");
00249                 return -1;
00250             }
00251             avio_skip(pb, size - 8);
00252             break;
00253         case MKTAG('w', 'a', 'v', 'e'):
00254             if ((uint64_t)size > (1<<30))
00255                 return -1;
00256             st->codec->extradata = av_mallocz(size + FF_INPUT_BUFFER_PADDING_SIZE);
00257             if (!st->codec->extradata)
00258                 return AVERROR(ENOMEM);
00259             st->codec->extradata_size = size;
00260             avio_read(pb, st->codec->extradata, size);
00261             break;
00262         case MKTAG('C','H','A','N'):
00263             if (size < 12)
00264                 return AVERROR_INVALIDDATA;
00265             ff_mov_read_chan(s, size, st->codec);
00266             break;
00267         default: /* Jump */
00268             if (size & 1)   /* Always even aligned */
00269                 size++;
00270             avio_skip(pb, size);
00271         }
00272     }
00273 
00274 got_sound:
00275     if (!st->codec->block_align) {
00276         av_log(s, AV_LOG_ERROR, "could not find COMM tag or invalid block_align value\n");
00277         return -1;
00278     }
00279 
00280     /* Now positioned, get the sound data start and end */
00281     avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);
00282     st->start_time = 0;
00283     st->duration = st->codec->frame_size ?
00284         st->nb_frames * st->codec->frame_size : st->nb_frames;
00285 
00286     /* Position the stream at the first block */
00287     avio_seek(pb, offset, SEEK_SET);
00288 
00289     return 0;
00290 }
00291 
00292 #define MAX_SIZE 4096
00293 
00294 static int aiff_read_packet(AVFormatContext *s,
00295                             AVPacket *pkt)
00296 {
00297     AVStream *st = s->streams[0];
00298     AIFFInputContext *aiff = s->priv_data;
00299     int64_t max_size;
00300     int res, size;
00301 
00302     /* calculate size of remaining data */
00303     max_size = aiff->data_end - avio_tell(s->pb);
00304     if (max_size <= 0)
00305         return AVERROR_EOF;
00306 
00307     /* Now for that packet */
00308     if (st->codec->block_align >= 33) // GSM, QCLP, IMA4
00309         size = st->codec->block_align;
00310     else
00311         size = (MAX_SIZE / st->codec->block_align) * st->codec->block_align;
00312     size = FFMIN(max_size, size);
00313     res = av_get_packet(s->pb, pkt, size);
00314     if (res < 0)
00315         return res;
00316 
00317     /* Only one stream in an AIFF file */
00318     pkt->stream_index = 0;
00319     return 0;
00320 }
00321 
00322 AVInputFormat ff_aiff_demuxer = {
00323     .name           = "aiff",
00324     .long_name      = NULL_IF_CONFIG_SMALL("Audio IFF"),
00325     .priv_data_size = sizeof(AIFFInputContext),
00326     .read_probe     = aiff_probe,
00327     .read_header    = aiff_read_header,
00328     .read_packet    = aiff_read_packet,
00329     .read_seek      = pcm_read_seek,
00330     .codec_tag= (const AVCodecTag* const []){ff_codec_aiff_tags, 0},
00331 };