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     int block_duration;
00036 } AIFFInputContext;
00037 
00038 static enum CodecID aiff_codec_get_id(int bps)
00039 {
00040     if (bps <= 8)
00041         return CODEC_ID_PCM_S8;
00042     if (bps <= 16)
00043         return CODEC_ID_PCM_S16BE;
00044     if (bps <= 24)
00045         return CODEC_ID_PCM_S24BE;
00046     if (bps <= 32)
00047         return CODEC_ID_PCM_S32BE;
00048 
00049     /* bigger than 32 isn't allowed  */
00050     return CODEC_ID_NONE;
00051 }
00052 
00053 /* returns the size of the found tag */
00054 static int get_tag(AVIOContext *pb, uint32_t * tag)
00055 {
00056     int size;
00057 
00058     if (url_feof(pb))
00059         return AVERROR(EIO);
00060 
00061     *tag = avio_rl32(pb);
00062     size = avio_rb32(pb);
00063 
00064     if (size < 0)
00065         size = 0x7fffffff;
00066 
00067     return size;
00068 }
00069 
00070 /* Metadata string read */
00071 static void get_meta(AVFormatContext *s, const char *key, int size)
00072 {
00073     uint8_t *str = av_malloc(size+1);
00074 
00075     if (str) {
00076         int res = avio_read(s->pb, str, size);
00077         if (res < 0){
00078             av_free(str);
00079             return;
00080         }
00081         size += (size&1)-res;
00082         str[res] = 0;
00083         av_dict_set(&s->metadata, key, str, AV_DICT_DONT_STRDUP_VAL);
00084     }else
00085         size+= size&1;
00086 
00087     avio_skip(s->pb, size);
00088 }
00089 
00090 /* Returns the number of sound data frames or negative on error */
00091 static unsigned int get_aiff_header(AVFormatContext *s, int size,
00092                                     unsigned version)
00093 {
00094     AVIOContext *pb        = s->pb;
00095     AVCodecContext *codec  = s->streams[0]->codec;
00096     AIFFInputContext *aiff = s->priv_data;
00097     int exp;
00098     uint64_t val;
00099     double sample_rate;
00100     unsigned int num_frames;
00101 
00102     if (size & 1)
00103         size++;
00104     codec->codec_type = AVMEDIA_TYPE_AUDIO;
00105     codec->channels = avio_rb16(pb);
00106     num_frames = avio_rb32(pb);
00107     codec->bits_per_coded_sample = avio_rb16(pb);
00108 
00109     exp = avio_rb16(pb);
00110     val = avio_rb64(pb);
00111     sample_rate = ldexp(val, exp - 16383 - 63);
00112     codec->sample_rate = sample_rate;
00113     size -= 18;
00114 
00115     /* get codec id for AIFF-C */
00116     if (version == AIFF_C_VERSION1) {
00117         codec->codec_tag = avio_rl32(pb);
00118         codec->codec_id  = ff_codec_get_id(ff_codec_aiff_tags, codec->codec_tag);
00119         size -= 4;
00120     }
00121 
00122     if (version != AIFF_C_VERSION1 || codec->codec_id == CODEC_ID_PCM_S16BE) {
00123         codec->codec_id = aiff_codec_get_id(codec->bits_per_coded_sample);
00124         codec->bits_per_coded_sample = av_get_bits_per_sample(codec->codec_id);
00125         aiff->block_duration = 1;
00126     } else {
00127         switch (codec->codec_id) {
00128         case CODEC_ID_PCM_F32BE:
00129         case CODEC_ID_PCM_F64BE:
00130         case CODEC_ID_PCM_S16LE:
00131         case CODEC_ID_PCM_ALAW:
00132         case CODEC_ID_PCM_MULAW:
00133             aiff->block_duration = 1;
00134             break;
00135         case CODEC_ID_ADPCM_IMA_QT:
00136             codec->block_align = 34*codec->channels;
00137             break;
00138         case CODEC_ID_MACE3:
00139             codec->block_align = 2*codec->channels;
00140             break;
00141         case CODEC_ID_MACE6:
00142             codec->block_align = 1*codec->channels;
00143             break;
00144         case CODEC_ID_GSM:
00145             codec->block_align = 33;
00146             break;
00147         case CODEC_ID_QCELP:
00148             codec->block_align = 35;
00149             break;
00150         default:
00151             aiff->block_duration = 1;
00152             break;
00153         }
00154         if (codec->block_align > 0)
00155             aiff->block_duration = av_get_audio_frame_duration(codec,
00156                                                                codec->block_align);
00157     }
00158 
00159     /* Block align needs to be computed in all cases, as the definition
00160      * is specific to applications -> here we use the WAVE format definition */
00161     if (!codec->block_align)
00162         codec->block_align = (codec->bits_per_coded_sample * codec->channels) >> 3;
00163 
00164     if (aiff->block_duration) {
00165         codec->bit_rate = codec->sample_rate * (codec->block_align << 3) /
00166                           aiff->block_duration;
00167     }
00168 
00169     /* Chunk is over */
00170     if (size)
00171         avio_skip(pb, size);
00172 
00173     return num_frames;
00174 }
00175 
00176 static int aiff_probe(AVProbeData *p)
00177 {
00178     /* check file header */
00179     if (p->buf[0] == 'F' && p->buf[1] == 'O' &&
00180         p->buf[2] == 'R' && p->buf[3] == 'M' &&
00181         p->buf[8] == 'A' && p->buf[9] == 'I' &&
00182         p->buf[10] == 'F' && (p->buf[11] == 'F' || p->buf[11] == 'C'))
00183         return AVPROBE_SCORE_MAX;
00184     else
00185         return 0;
00186 }
00187 
00188 /* aiff input */
00189 static int aiff_read_header(AVFormatContext *s)
00190 {
00191     int size, filesize;
00192     int64_t offset = 0;
00193     uint32_t tag;
00194     unsigned version = AIFF_C_VERSION1;
00195     AVIOContext *pb = s->pb;
00196     AVStream * st;
00197     AIFFInputContext *aiff = s->priv_data;
00198 
00199     /* check FORM header */
00200     filesize = get_tag(pb, &tag);
00201     if (filesize < 0 || tag != MKTAG('F', 'O', 'R', 'M'))
00202         return AVERROR_INVALIDDATA;
00203 
00204     /* AIFF data type */
00205     tag = avio_rl32(pb);
00206     if (tag == MKTAG('A', 'I', 'F', 'F'))       /* Got an AIFF file */
00207         version = AIFF;
00208     else if (tag != MKTAG('A', 'I', 'F', 'C'))  /* An AIFF-C file then */
00209         return AVERROR_INVALIDDATA;
00210 
00211     filesize -= 4;
00212 
00213     st = avformat_new_stream(s, NULL);
00214     if (!st)
00215         return AVERROR(ENOMEM);
00216 
00217     while (filesize > 0) {
00218         /* parse different chunks */
00219         size = get_tag(pb, &tag);
00220         if (size < 0)
00221             return size;
00222 
00223         filesize -= size + 8;
00224 
00225         switch (tag) {
00226         case MKTAG('C', 'O', 'M', 'M'):     /* Common chunk */
00227             /* Then for the complete header info */
00228             st->nb_frames = get_aiff_header(s, size, version);
00229             if (st->nb_frames < 0)
00230                 return st->nb_frames;
00231             if (offset > 0) // COMM is after SSND
00232                 goto got_sound;
00233             break;
00234         case MKTAG('F', 'V', 'E', 'R'):     /* Version chunk */
00235             version = avio_rb32(pb);
00236             break;
00237         case MKTAG('N', 'A', 'M', 'E'):     /* Sample name chunk */
00238             get_meta(s, "title"    , size);
00239             break;
00240         case MKTAG('A', 'U', 'T', 'H'):     /* Author chunk */
00241             get_meta(s, "author"   , size);
00242             break;
00243         case MKTAG('(', 'c', ')', ' '):     /* Copyright chunk */
00244             get_meta(s, "copyright", size);
00245             break;
00246         case MKTAG('A', 'N', 'N', 'O'):     /* Annotation chunk */
00247             get_meta(s, "comment"  , size);
00248             break;
00249         case MKTAG('S', 'S', 'N', 'D'):     /* Sampled sound chunk */
00250             aiff->data_end = avio_tell(pb) + size;
00251             offset = avio_rb32(pb);      /* Offset of sound data */
00252             avio_rb32(pb);               /* BlockSize... don't care */
00253             offset += avio_tell(pb);    /* Compute absolute data offset */
00254             if (st->codec->block_align)    /* Assume COMM already parsed */
00255                 goto got_sound;
00256             if (!pb->seekable) {
00257                 av_log(s, AV_LOG_ERROR, "file is not seekable\n");
00258                 return -1;
00259             }
00260             avio_skip(pb, size - 8);
00261             break;
00262         case MKTAG('w', 'a', 'v', 'e'):
00263             if ((uint64_t)size > (1<<30))
00264                 return -1;
00265             st->codec->extradata = av_mallocz(size + FF_INPUT_BUFFER_PADDING_SIZE);
00266             if (!st->codec->extradata)
00267                 return AVERROR(ENOMEM);
00268             st->codec->extradata_size = size;
00269             avio_read(pb, st->codec->extradata, size);
00270             break;
00271         case MKTAG('C','H','A','N'):
00272             if (size < 12)
00273                 return AVERROR_INVALIDDATA;
00274             ff_mov_read_chan(s, size, st->codec);
00275             break;
00276         default: /* Jump */
00277             if (size & 1)   /* Always even aligned */
00278                 size++;
00279             avio_skip(pb, size);
00280         }
00281     }
00282 
00283 got_sound:
00284     if (!st->codec->block_align) {
00285         av_log(s, AV_LOG_ERROR, "could not find COMM tag or invalid block_align value\n");
00286         return -1;
00287     }
00288 
00289     /* Now positioned, get the sound data start and end */
00290     avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);
00291     st->start_time = 0;
00292     st->duration = st->nb_frames * aiff->block_duration;
00293 
00294     /* Position the stream at the first block */
00295     avio_seek(pb, offset, SEEK_SET);
00296 
00297     return 0;
00298 }
00299 
00300 #define MAX_SIZE 4096
00301 
00302 static int aiff_read_packet(AVFormatContext *s,
00303                             AVPacket *pkt)
00304 {
00305     AVStream *st = s->streams[0];
00306     AIFFInputContext *aiff = s->priv_data;
00307     int64_t max_size;
00308     int res, size;
00309 
00310     /* calculate size of remaining data */
00311     max_size = aiff->data_end - avio_tell(s->pb);
00312     if (max_size <= 0)
00313         return AVERROR_EOF;
00314 
00315     /* Now for that packet */
00316     if (st->codec->block_align >= 33) // GSM, QCLP, IMA4
00317         size = st->codec->block_align;
00318     else
00319         size = (MAX_SIZE / st->codec->block_align) * st->codec->block_align;
00320     size = FFMIN(max_size, size);
00321     res = av_get_packet(s->pb, pkt, size);
00322     if (res < 0)
00323         return res;
00324 
00325     if (size >= st->codec->block_align)
00326         pkt->flags &= ~AV_PKT_FLAG_CORRUPT;
00327     /* Only one stream in an AIFF file */
00328     pkt->stream_index = 0;
00329     pkt->duration     = (res / st->codec->block_align) * aiff->block_duration;
00330     return 0;
00331 }
00332 
00333 AVInputFormat ff_aiff_demuxer = {
00334     .name           = "aiff",
00335     .long_name      = NULL_IF_CONFIG_SMALL("Audio IFF"),
00336     .priv_data_size = sizeof(AIFFInputContext),
00337     .read_probe     = aiff_probe,
00338     .read_header    = aiff_read_header,
00339     .read_packet    = aiff_read_packet,
00340     .read_seek      = ff_pcm_read_seek,
00341     .codec_tag      = (const AVCodecTag* const []){ ff_codec_aiff_tags, 0 },
00342 };