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libavformat/aiffenc.c

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00001 /*
00002  * AIFF/AIFF-C muxer
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.h"
00023 #include "avformat.h"
00024 #include "internal.h"
00025 #include "aiff.h"
00026 #include "avio_internal.h"
00027 #include "isom.h"
00028 
00029 typedef struct {
00030     int64_t form;
00031     int64_t frames;
00032     int64_t ssnd;
00033 } AIFFOutputContext;
00034 
00035 static int aiff_write_header(AVFormatContext *s)
00036 {
00037     AIFFOutputContext *aiff = s->priv_data;
00038     AVIOContext *pb = s->pb;
00039     AVCodecContext *enc = s->streams[0]->codec;
00040     uint64_t sample_rate;
00041     int aifc = 0;
00042 
00043     /* First verify if format is ok */
00044     if (!enc->codec_tag)
00045         return -1;
00046     if (enc->codec_tag != MKTAG('N','O','N','E'))
00047         aifc = 1;
00048 
00049     /* FORM AIFF header */
00050     ffio_wfourcc(pb, "FORM");
00051     aiff->form = avio_tell(pb);
00052     avio_wb32(pb, 0);                    /* file length */
00053     ffio_wfourcc(pb, aifc ? "AIFC" : "AIFF");
00054 
00055     if (aifc) { // compressed audio
00056         enc->bits_per_coded_sample = 16;
00057         if (!enc->block_align) {
00058             av_log(s, AV_LOG_ERROR, "block align not set\n");
00059             return -1;
00060         }
00061         /* Version chunk */
00062         ffio_wfourcc(pb, "FVER");
00063         avio_wb32(pb, 4);
00064         avio_wb32(pb, 0xA2805140);
00065     }
00066 
00067     if (enc->channels > 2 && enc->channel_layout) {
00068         ffio_wfourcc(pb, "CHAN");
00069         avio_wb32(pb, 12);
00070         ff_mov_write_chan(pb, enc->channel_layout);
00071     }
00072 
00073     /* Common chunk */
00074     ffio_wfourcc(pb, "COMM");
00075     avio_wb32(pb, aifc ? 24 : 18); /* size */
00076     avio_wb16(pb, enc->channels);  /* Number of channels */
00077 
00078     aiff->frames = avio_tell(pb);
00079     avio_wb32(pb, 0);              /* Number of frames */
00080 
00081     if (!enc->bits_per_coded_sample)
00082         enc->bits_per_coded_sample = av_get_bits_per_sample(enc->codec_id);
00083     if (!enc->bits_per_coded_sample) {
00084         av_log(s, AV_LOG_ERROR, "could not compute bits per sample\n");
00085         return -1;
00086     }
00087     if (!enc->block_align)
00088         enc->block_align = (enc->bits_per_coded_sample * enc->channels) >> 3;
00089 
00090     avio_wb16(pb, enc->bits_per_coded_sample); /* Sample size */
00091 
00092     sample_rate = av_double2int(enc->sample_rate);
00093     avio_wb16(pb, (sample_rate >> 52) + (16383 - 1023));
00094     avio_wb64(pb, UINT64_C(1) << 63 | sample_rate << 11);
00095 
00096     if (aifc) {
00097         avio_wl32(pb, enc->codec_tag);
00098         avio_wb16(pb, 0);
00099     }
00100 
00101     /* Sound data chunk */
00102     ffio_wfourcc(pb, "SSND");
00103     aiff->ssnd = avio_tell(pb);         /* Sound chunk size */
00104     avio_wb32(pb, 0);                    /* Sound samples data size */
00105     avio_wb32(pb, 0);                    /* Data offset */
00106     avio_wb32(pb, 0);                    /* Block-size (block align) */
00107 
00108     avpriv_set_pts_info(s->streams[0], 64, 1, s->streams[0]->codec->sample_rate);
00109 
00110     /* Data is starting here */
00111     avio_flush(pb);
00112 
00113     return 0;
00114 }
00115 
00116 static int aiff_write_packet(AVFormatContext *s, AVPacket *pkt)
00117 {
00118     AVIOContext *pb = s->pb;
00119     avio_write(pb, pkt->data, pkt->size);
00120     return 0;
00121 }
00122 
00123 static int aiff_write_trailer(AVFormatContext *s)
00124 {
00125     AVIOContext *pb = s->pb;
00126     AIFFOutputContext *aiff = s->priv_data;
00127     AVCodecContext *enc = s->streams[0]->codec;
00128 
00129     /* Chunks sizes must be even */
00130     int64_t file_size, end_size;
00131     end_size = file_size = avio_tell(pb);
00132     if (file_size & 1) {
00133         avio_w8(pb, 0);
00134         end_size++;
00135     }
00136 
00137     if (s->pb->seekable) {
00138         /* File length */
00139         avio_seek(pb, aiff->form, SEEK_SET);
00140         avio_wb32(pb, file_size - aiff->form - 4);
00141 
00142         /* Number of sample frames */
00143         avio_seek(pb, aiff->frames, SEEK_SET);
00144         avio_wb32(pb, (file_size-aiff->ssnd-12)/enc->block_align);
00145 
00146         /* Sound Data chunk size */
00147         avio_seek(pb, aiff->ssnd, SEEK_SET);
00148         avio_wb32(pb, file_size - aiff->ssnd - 4);
00149 
00150         /* return to the end */
00151         avio_seek(pb, end_size, SEEK_SET);
00152 
00153         avio_flush(pb);
00154     }
00155 
00156     return 0;
00157 }
00158 
00159 AVOutputFormat ff_aiff_muxer = {
00160     .name              = "aiff",
00161     .long_name         = NULL_IF_CONFIG_SMALL("Audio IFF"),
00162     .mime_type         = "audio/aiff",
00163     .extensions        = "aif,aiff,afc,aifc",
00164     .priv_data_size    = sizeof(AIFFOutputContext),
00165     .audio_codec       = CODEC_ID_PCM_S16BE,
00166     .video_codec       = CODEC_ID_NONE,
00167     .write_header      = aiff_write_header,
00168     .write_packet      = aiff_write_packet,
00169     .write_trailer     = aiff_write_trailer,
00170     .codec_tag= (const AVCodecTag* const []){ff_codec_aiff_tags, 0},
00171 };
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