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 "avformat.h"
00024 #include "raw.h"
00025 #include "aiff.h"
00026 
00027 #define AIFF                    0
00028 #define AIFF_C_VERSION1         0xA2805140
00029 
00030 typedef struct {
00031     int64_t data_end;
00032 } AIFFInputContext;
00033 
00034 static enum CodecID aiff_codec_get_id(int bps)
00035 {
00036     if (bps <= 8)
00037         return CODEC_ID_PCM_S8;
00038     if (bps <= 16)
00039         return CODEC_ID_PCM_S16BE;
00040     if (bps <= 24)
00041         return CODEC_ID_PCM_S24BE;
00042     if (bps <= 32)
00043         return CODEC_ID_PCM_S32BE;
00044 
00045     /* bigger than 32 isn't allowed  */
00046     return CODEC_ID_NONE;
00047 }
00048 
00049 /* returns the size of the found tag */
00050 static int get_tag(ByteIOContext *pb, uint32_t * tag)
00051 {
00052     int size;
00053 
00054     if (url_feof(pb))
00055         return AVERROR(EIO);
00056 
00057     *tag = get_le32(pb);
00058     size = get_be32(pb);
00059 
00060     if (size < 0)
00061         size = 0x7fffffff;
00062 
00063     return size;
00064 }
00065 
00066 /* Metadata string read */
00067 static void get_meta(AVFormatContext *s, const char *key, int size)
00068 {
00069     uint8_t *str = av_malloc(size+1);
00070     int res;
00071 
00072     if (!str) {
00073         url_fskip(s->pb, size);
00074         return;
00075     }
00076 
00077     res = get_buffer(s->pb, str, size);
00078     if (res < 0)
00079         return;
00080 
00081     str[res] = 0;
00082     av_metadata_set2(&s->metadata, key, str, AV_METADATA_DONT_STRDUP_VAL);
00083 }
00084 
00085 /* Returns the number of sound data frames or negative on error */
00086 static unsigned int get_aiff_header(ByteIOContext *pb, AVCodecContext *codec,
00087                              int size, unsigned version)
00088 {
00089     AVExtFloat ext;
00090     double sample_rate;
00091     unsigned int num_frames;
00092 
00093     if (size & 1)
00094         size++;
00095     codec->codec_type = AVMEDIA_TYPE_AUDIO;
00096     codec->channels = get_be16(pb);
00097     num_frames = get_be32(pb);
00098     codec->bits_per_coded_sample = get_be16(pb);
00099 
00100     get_buffer(pb, (uint8_t*)&ext, sizeof(ext));/* Sample rate is in */
00101     sample_rate = av_ext2dbl(ext);          /* 80 bits BE IEEE extended float */
00102     codec->sample_rate = sample_rate;
00103     size -= 18;
00104 
00105     /* Got an AIFF-C? */
00106     if (version == AIFF_C_VERSION1) {
00107         codec->codec_tag = get_le32(pb);
00108         codec->codec_id  = ff_codec_get_id(ff_codec_aiff_tags, codec->codec_tag);
00109 
00110         switch (codec->codec_id) {
00111         case CODEC_ID_PCM_S16BE:
00112             codec->codec_id = aiff_codec_get_id(codec->bits_per_coded_sample);
00113             codec->bits_per_coded_sample = av_get_bits_per_sample(codec->codec_id);
00114             break;
00115         case CODEC_ID_ADPCM_IMA_QT:
00116             codec->block_align = 34*codec->channels;
00117             codec->frame_size = 64;
00118             break;
00119         case CODEC_ID_MACE3:
00120             codec->block_align = 2*codec->channels;
00121             codec->frame_size = 6;
00122             break;
00123         case CODEC_ID_MACE6:
00124             codec->block_align = 1*codec->channels;
00125             codec->frame_size = 6;
00126             break;
00127         case CODEC_ID_GSM:
00128             codec->block_align = 33;
00129             codec->frame_size = 160;
00130             break;
00131         case CODEC_ID_QCELP:
00132             codec->block_align = 35;
00133             codec->frame_size= 160;
00134             break;
00135         default:
00136             break;
00137         }
00138         size -= 4;
00139     } else {
00140         /* Need the codec type */
00141         codec->codec_id = aiff_codec_get_id(codec->bits_per_coded_sample);
00142         codec->bits_per_coded_sample = av_get_bits_per_sample(codec->codec_id);
00143     }
00144 
00145     /* Block align needs to be computed in all cases, as the definition
00146      * is specific to applications -> here we use the WAVE format definition */
00147     if (!codec->block_align)
00148         codec->block_align = (codec->bits_per_coded_sample * codec->channels) >> 3;
00149 
00150     codec->bit_rate = (codec->frame_size ? codec->sample_rate/codec->frame_size :
00151                        codec->sample_rate) * (codec->block_align << 3);
00152 
00153     /* Chunk is over */
00154     if (size)
00155         url_fseek(pb, size, SEEK_CUR);
00156 
00157     return num_frames;
00158 }
00159 
00160 static int aiff_probe(AVProbeData *p)
00161 {
00162     /* check file header */
00163     if (p->buf[0] == 'F' && p->buf[1] == 'O' &&
00164         p->buf[2] == 'R' && p->buf[3] == 'M' &&
00165         p->buf[8] == 'A' && p->buf[9] == 'I' &&
00166         p->buf[10] == 'F' && (p->buf[11] == 'F' || p->buf[11] == 'C'))
00167         return AVPROBE_SCORE_MAX;
00168     else
00169         return 0;
00170 }
00171 
00172 /* aiff input */
00173 static int aiff_read_header(AVFormatContext *s,
00174                             AVFormatParameters *ap)
00175 {
00176     int size, filesize;
00177     int64_t offset = 0;
00178     uint32_t tag;
00179     unsigned version = AIFF_C_VERSION1;
00180     ByteIOContext *pb = s->pb;
00181     AVStream * st;
00182     AIFFInputContext *aiff = s->priv_data;
00183 
00184     /* check FORM header */
00185     filesize = get_tag(pb, &tag);
00186     if (filesize < 0 || tag != MKTAG('F', 'O', 'R', 'M'))
00187         return AVERROR_INVALIDDATA;
00188 
00189     /* AIFF data type */
00190     tag = get_le32(pb);
00191     if (tag == MKTAG('A', 'I', 'F', 'F'))       /* Got an AIFF file */
00192         version = AIFF;
00193     else if (tag != MKTAG('A', 'I', 'F', 'C'))  /* An AIFF-C file then */
00194         return AVERROR_INVALIDDATA;
00195 
00196     filesize -= 4;
00197 
00198     st = av_new_stream(s, 0);
00199     if (!st)
00200         return AVERROR(ENOMEM);
00201 
00202     while (filesize > 0) {
00203         /* parse different chunks */
00204         size = get_tag(pb, &tag);
00205         if (size < 0)
00206             return size;
00207 
00208         filesize -= size + 8;
00209 
00210         switch (tag) {
00211         case MKTAG('C', 'O', 'M', 'M'):     /* Common chunk */
00212             /* Then for the complete header info */
00213             st->nb_frames = get_aiff_header(pb, st->codec, size, version);
00214             if (st->nb_frames < 0)
00215                 return st->nb_frames;
00216             if (offset > 0) // COMM is after SSND
00217                 goto got_sound;
00218             break;
00219         case MKTAG('F', 'V', 'E', 'R'):     /* Version chunk */
00220             version = get_be32(pb);
00221             break;
00222         case MKTAG('N', 'A', 'M', 'E'):     /* Sample name chunk */
00223             get_meta(s, "title"    , size);
00224             break;
00225         case MKTAG('A', 'U', 'T', 'H'):     /* Author chunk */
00226             get_meta(s, "author"   , size);
00227             break;
00228         case MKTAG('(', 'c', ')', ' '):     /* Copyright chunk */
00229             get_meta(s, "copyright", size);
00230             break;
00231         case MKTAG('A', 'N', 'N', 'O'):     /* Annotation chunk */
00232             get_meta(s, "comment"  , size);
00233             break;
00234         case MKTAG('S', 'S', 'N', 'D'):     /* Sampled sound chunk */
00235             aiff->data_end = url_ftell(pb) + size;
00236             offset = get_be32(pb);      /* Offset of sound data */
00237             get_be32(pb);               /* BlockSize... don't care */
00238             offset += url_ftell(pb);    /* Compute absolute data offset */
00239             if (st->codec->block_align)    /* Assume COMM already parsed */
00240                 goto got_sound;
00241             if (url_is_streamed(pb)) {
00242                 av_log(s, AV_LOG_ERROR, "file is not seekable\n");
00243                 return -1;
00244             }
00245             url_fskip(pb, size - 8);
00246             break;
00247         case MKTAG('w', 'a', 'v', 'e'):
00248             if ((uint64_t)size > (1<<30))
00249                 return -1;
00250             st->codec->extradata = av_mallocz(size + FF_INPUT_BUFFER_PADDING_SIZE);
00251             if (!st->codec->extradata)
00252                 return AVERROR(ENOMEM);
00253             st->codec->extradata_size = size;
00254             get_buffer(pb, st->codec->extradata, size);
00255             break;
00256         default: /* Jump */
00257             if (size & 1)   /* Always even aligned */
00258                 size++;
00259             url_fskip (pb, size);
00260         }
00261     }
00262 
00263     if (!st->codec->block_align) {
00264         av_log(s, AV_LOG_ERROR, "could not find COMM tag\n");
00265         return -1;
00266     }
00267 
00268 got_sound:
00269     /* Now positioned, get the sound data start and end */
00270     if (st->nb_frames)
00271         s->file_size = st->nb_frames * st->codec->block_align;
00272 
00273     av_set_pts_info(st, 64, 1, st->codec->sample_rate);
00274     st->start_time = 0;
00275     st->duration = st->codec->frame_size ?
00276         st->nb_frames * st->codec->frame_size : st->nb_frames;
00277 
00278     /* Position the stream at the first block */
00279     url_fseek(pb, offset, SEEK_SET);
00280 
00281     return 0;
00282 }
00283 
00284 #define MAX_SIZE 4096
00285 
00286 static int aiff_read_packet(AVFormatContext *s,
00287                             AVPacket *pkt)
00288 {
00289     AVStream *st = s->streams[0];
00290     AIFFInputContext *aiff = s->priv_data;
00291     int64_t max_size;
00292     int res, size;
00293 
00294     /* calculate size of remaining data */
00295     max_size = aiff->data_end - url_ftell(s->pb);
00296     if (max_size <= 0)
00297         return AVERROR_EOF;
00298 
00299     /* Now for that packet */
00300     if (st->codec->block_align >= 33) // GSM, QCLP, IMA4
00301         size = st->codec->block_align;
00302     else
00303         size = (MAX_SIZE / st->codec->block_align) * st->codec->block_align;
00304     size = FFMIN(max_size, size);
00305     res = av_get_packet(s->pb, pkt, size);
00306     if (res < 0)
00307         return res;
00308 
00309     /* Only one stream in an AIFF file */
00310     pkt->stream_index = 0;
00311     return 0;
00312 }
00313 
00314 AVInputFormat aiff_demuxer = {
00315     "aiff",
00316     NULL_IF_CONFIG_SMALL("Audio IFF"),
00317     sizeof(AIFFInputContext),
00318     aiff_probe,
00319     aiff_read_header,
00320     aiff_read_packet,
00321     NULL,
00322     pcm_read_seek,
00323     .codec_tag= (const AVCodecTag* const []){ff_codec_aiff_tags, 0},
00324 };