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/intfloat_readwrite.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     AVExtFloat ext;
00094     double sample_rate;
00095     unsigned int num_frames;
00096 
00097     if (size & 1)
00098         size++;
00099     codec->codec_type = AVMEDIA_TYPE_AUDIO;
00100     codec->channels = avio_rb16(pb);
00101     num_frames = avio_rb32(pb);
00102     codec->bits_per_coded_sample = avio_rb16(pb);
00103 
00104     avio_read(pb, (uint8_t*)&ext, sizeof(ext));/* Sample rate is in */
00105     sample_rate = av_ext2dbl(ext);          /* 80 bits BE IEEE extended float */
00106     codec->sample_rate = sample_rate;
00107     size -= 18;
00108 
00109     /* Got an AIFF-C? */
00110     if (version == AIFF_C_VERSION1) {
00111         codec->codec_tag = avio_rl32(pb);
00112         codec->codec_id  = ff_codec_get_id(ff_codec_aiff_tags, codec->codec_tag);
00113 
00114         switch (codec->codec_id) {
00115         case CODEC_ID_PCM_S16BE:
00116             codec->codec_id = aiff_codec_get_id(codec->bits_per_coded_sample);
00117             codec->bits_per_coded_sample = av_get_bits_per_sample(codec->codec_id);
00118             break;
00119         case CODEC_ID_ADPCM_IMA_QT:
00120             codec->block_align = 34*codec->channels;
00121             codec->frame_size = 64;
00122             break;
00123         case CODEC_ID_MACE3:
00124             codec->block_align = 2*codec->channels;
00125             codec->frame_size = 6;
00126             break;
00127         case CODEC_ID_MACE6:
00128             codec->block_align = 1*codec->channels;
00129             codec->frame_size = 6;
00130             break;
00131         case CODEC_ID_GSM:
00132             codec->block_align = 33;
00133             codec->frame_size = 160;
00134             break;
00135         case CODEC_ID_QCELP:
00136             codec->block_align = 35;
00137             codec->frame_size= 160;
00138             break;
00139         default:
00140             break;
00141         }
00142         size -= 4;
00143     } else {
00144         /* Need the codec type */
00145         codec->codec_id = aiff_codec_get_id(codec->bits_per_coded_sample);
00146         codec->bits_per_coded_sample = av_get_bits_per_sample(codec->codec_id);
00147     }
00148 
00149     /* Block align needs to be computed in all cases, as the definition
00150      * is specific to applications -> here we use the WAVE format definition */
00151     if (!codec->block_align)
00152         codec->block_align = (codec->bits_per_coded_sample * codec->channels) >> 3;
00153 
00154     codec->bit_rate = (codec->frame_size ? codec->sample_rate/codec->frame_size :
00155                        codec->sample_rate) * (codec->block_align << 3);
00156 
00157     /* Chunk is over */
00158     if (size)
00159         avio_skip(pb, size);
00160 
00161     return num_frames;
00162 }
00163 
00164 static int aiff_probe(AVProbeData *p)
00165 {
00166     /* check file header */
00167     if (p->buf[0] == 'F' && p->buf[1] == 'O' &&
00168         p->buf[2] == 'R' && p->buf[3] == 'M' &&
00169         p->buf[8] == 'A' && p->buf[9] == 'I' &&
00170         p->buf[10] == 'F' && (p->buf[11] == 'F' || p->buf[11] == 'C'))
00171         return AVPROBE_SCORE_MAX;
00172     else
00173         return 0;
00174 }
00175 
00176 /* aiff input */
00177 static int aiff_read_header(AVFormatContext *s,
00178                             AVFormatParameters *ap)
00179 {
00180     int size, filesize;
00181     int64_t offset = 0;
00182     uint32_t tag;
00183     unsigned version = AIFF_C_VERSION1;
00184     AVIOContext *pb = s->pb;
00185     AVStream * st;
00186     AIFFInputContext *aiff = s->priv_data;
00187 
00188     /* check FORM header */
00189     filesize = get_tag(pb, &tag);
00190     if (filesize < 0 || tag != MKTAG('F', 'O', 'R', 'M'))
00191         return AVERROR_INVALIDDATA;
00192 
00193     /* AIFF data type */
00194     tag = avio_rl32(pb);
00195     if (tag == MKTAG('A', 'I', 'F', 'F'))       /* Got an AIFF file */
00196         version = AIFF;
00197     else if (tag != MKTAG('A', 'I', 'F', 'C'))  /* An AIFF-C file then */
00198         return AVERROR_INVALIDDATA;
00199 
00200     filesize -= 4;
00201 
00202     st = avformat_new_stream(s, NULL);
00203     if (!st)
00204         return AVERROR(ENOMEM);
00205 
00206     while (filesize > 0) {
00207         /* parse different chunks */
00208         size = get_tag(pb, &tag);
00209         if (size < 0)
00210             return size;
00211 
00212         filesize -= size + 8;
00213 
00214         switch (tag) {
00215         case MKTAG('C', 'O', 'M', 'M'):     /* Common chunk */
00216             /* Then for the complete header info */
00217             st->nb_frames = get_aiff_header(pb, st->codec, size, version);
00218             if (st->nb_frames < 0)
00219                 return st->nb_frames;
00220             if (offset > 0) // COMM is after SSND
00221                 goto got_sound;
00222             break;
00223         case MKTAG('F', 'V', 'E', 'R'):     /* Version chunk */
00224             version = avio_rb32(pb);
00225             break;
00226         case MKTAG('N', 'A', 'M', 'E'):     /* Sample name chunk */
00227             get_meta(s, "title"    , size);
00228             break;
00229         case MKTAG('A', 'U', 'T', 'H'):     /* Author chunk */
00230             get_meta(s, "author"   , size);
00231             break;
00232         case MKTAG('(', 'c', ')', ' '):     /* Copyright chunk */
00233             get_meta(s, "copyright", size);
00234             break;
00235         case MKTAG('A', 'N', 'N', 'O'):     /* Annotation chunk */
00236             get_meta(s, "comment"  , size);
00237             break;
00238         case MKTAG('S', 'S', 'N', 'D'):     /* Sampled sound chunk */
00239             aiff->data_end = avio_tell(pb) + size;
00240             offset = avio_rb32(pb);      /* Offset of sound data */
00241             avio_rb32(pb);               /* BlockSize... don't care */
00242             offset += avio_tell(pb);    /* Compute absolute data offset */
00243             if (st->codec->block_align)    /* Assume COMM already parsed */
00244                 goto got_sound;
00245             if (!pb->seekable) {
00246                 av_log(s, AV_LOG_ERROR, "file is not seekable\n");
00247                 return -1;
00248             }
00249             avio_skip(pb, size - 8);
00250             break;
00251         case MKTAG('w', 'a', 'v', 'e'):
00252             if ((uint64_t)size > (1<<30))
00253                 return -1;
00254             st->codec->extradata = av_mallocz(size + FF_INPUT_BUFFER_PADDING_SIZE);
00255             if (!st->codec->extradata)
00256                 return AVERROR(ENOMEM);
00257             st->codec->extradata_size = size;
00258             avio_read(pb, st->codec->extradata, size);
00259             break;
00260         case MKTAG('C','H','A','N'):
00261             if (size < 12)
00262                 return AVERROR_INVALIDDATA;
00263             ff_mov_read_chan(s, size, st->codec);
00264             break;
00265         default: /* Jump */
00266             if (size & 1)   /* Always even aligned */
00267                 size++;
00268             avio_skip(pb, size);
00269         }
00270     }
00271 
00272     if (!st->codec->block_align) {
00273         av_log(s, AV_LOG_ERROR, "could not find COMM tag\n");
00274         return -1;
00275     }
00276 
00277 got_sound:
00278     /* Now positioned, get the sound data start and end */
00279     avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);
00280     st->start_time = 0;
00281     st->duration = st->codec->frame_size ?
00282         st->nb_frames * st->codec->frame_size : st->nb_frames;
00283 
00284     /* Position the stream at the first block */
00285     avio_seek(pb, offset, SEEK_SET);
00286 
00287     return 0;
00288 }
00289 
00290 #define MAX_SIZE 4096
00291 
00292 static int aiff_read_packet(AVFormatContext *s,
00293                             AVPacket *pkt)
00294 {
00295     AVStream *st = s->streams[0];
00296     AIFFInputContext *aiff = s->priv_data;
00297     int64_t max_size;
00298     int res, size;
00299 
00300     /* calculate size of remaining data */
00301     max_size = aiff->data_end - avio_tell(s->pb);
00302     if (max_size <= 0)
00303         return AVERROR_EOF;
00304 
00305     /* Now for that packet */
00306     if (st->codec->block_align >= 33) // GSM, QCLP, IMA4
00307         size = st->codec->block_align;
00308     else
00309         size = (MAX_SIZE / st->codec->block_align) * st->codec->block_align;
00310     size = FFMIN(max_size, size);
00311     res = av_get_packet(s->pb, pkt, size);
00312     if (res < 0)
00313         return res;
00314 
00315     /* Only one stream in an AIFF file */
00316     pkt->stream_index = 0;
00317     return 0;
00318 }
00319 
00320 AVInputFormat ff_aiff_demuxer = {
00321     .name           = "aiff",
00322     .long_name      = NULL_IF_CONFIG_SMALL("Audio IFF"),
00323     .priv_data_size = sizeof(AIFFInputContext),
00324     .read_probe     = aiff_probe,
00325     .read_header    = aiff_read_header,
00326     .read_packet    = aiff_read_packet,
00327     .read_seek      = pcm_read_seek,
00328     .codec_tag= (const AVCodecTag* const []){ff_codec_aiff_tags, 0},
00329 };