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  • /*
     * AIFF/AIFF-C muxer
     * Copyright (c) 2006  Patrick Guimond
     *
     * This file is part of FFmpeg.
     *
     * FFmpeg is free software; you can redistribute it and/or
     * modify it under the terms of the GNU Lesser General Public
     * License as published by the Free Software Foundation; either
     * version 2.1 of the License, or (at your option) any later version.
     *
     * FFmpeg is distributed in the hope that it will be useful,
     * but WITHOUT ANY WARRANTY; without even the implied warranty of
     * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     * Lesser General Public License for more details.
     *
     * You should have received a copy of the GNU Lesser General Public
     * License along with FFmpeg; if not, write to the Free Software
     * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
     */
    
    #include "avformat.h"
    #include "aiff.h"
    
    typedef struct {
        int64_t form;
        int64_t frames;
        int64_t ssnd;
    } AIFFOutputContext;
    
    static int aiff_write_header(AVFormatContext *s)
    {
        AIFFOutputContext *aiff = s->priv_data;
        ByteIOContext *pb = s->pb;
        AVCodecContext *enc = s->streams[0]->codec;
        AVExtFloat sample_rate;
        int aifc = 0;
    
        /* First verify if format is ok */
        if (!enc->codec_tag)
            return -1;
        if (enc->codec_tag != MKTAG('N','O','N','E'))
            aifc = 1;
    
        /* FORM AIFF header */
        put_tag(pb, "FORM");
        aiff->form = url_ftell(pb);
        put_be32(pb, 0);                    /* file length */
        put_tag(pb, aifc ? "AIFC" : "AIFF");
    
        if (aifc) { // compressed audio
            enc->bits_per_coded_sample = 16;
            if (!enc->block_align) {
                av_log(s, AV_LOG_ERROR, "block align not set\n");
                return -1;
            }
            /* Version chunk */
            put_tag(pb, "FVER");
            put_be32(pb, 4);
            put_be32(pb, 0xA2805140);
        }
    
        /* Common chunk */
        put_tag(pb, "COMM");
        put_be32(pb, aifc ? 24 : 18); /* size */
        put_be16(pb, enc->channels);  /* Number of channels */
    
        aiff->frames = url_ftell(pb);
        put_be32(pb, 0);              /* Number of frames */
    
        if (!enc->bits_per_coded_sample)
            enc->bits_per_coded_sample = av_get_bits_per_sample(enc->codec_id);
        if (!enc->bits_per_coded_sample) {
            av_log(s, AV_LOG_ERROR, "could not compute bits per sample\n");
            return -1;
        }
        if (!enc->block_align)
            enc->block_align = (enc->bits_per_coded_sample * enc->channels) >> 3;
    
        put_be16(pb, enc->bits_per_coded_sample); /* Sample size */
    
        sample_rate = av_dbl2ext((double)enc->sample_rate);
        put_buffer(pb, (uint8_t*)&sample_rate, sizeof(sample_rate));
    
        if (aifc) {
            put_le32(pb, enc->codec_tag);
            put_be16(pb, 0);
        }
    
        /* Sound data chunk */
        put_tag(pb, "SSND");
        aiff->ssnd = url_ftell(pb);         /* Sound chunk size */
        put_be32(pb, 0);                    /* Sound samples data size */
        put_be32(pb, 0);                    /* Data offset */
        put_be32(pb, 0);                    /* Block-size (block align) */
    
        av_set_pts_info(s->streams[0], 64, 1, s->streams[0]->codec->sample_rate);
    
        /* Data is starting here */
        put_flush_packet(pb);
    
        return 0;
    }
    
    static int aiff_write_packet(AVFormatContext *s, AVPacket *pkt)
    {
        ByteIOContext *pb = s->pb;
        put_buffer(pb, pkt->data, pkt->size);
        return 0;
    }
    
    static int aiff_write_trailer(AVFormatContext *s)
    {
        ByteIOContext *pb = s->pb;
        AIFFOutputContext *aiff = s->priv_data;
        AVCodecContext *enc = s->streams[0]->codec;
    
        /* Chunks sizes must be even */
        int64_t file_size, end_size;
        end_size = file_size = url_ftell(pb);
        if (file_size & 1) {
            put_byte(pb, 0);
            end_size++;
        }
    
        if (!url_is_streamed(s->pb)) {
            /* File length */
            url_fseek(pb, aiff->form, SEEK_SET);
            put_be32(pb, file_size - aiff->form - 4);
    
            /* Number of sample frames */
            url_fseek(pb, aiff->frames, SEEK_SET);
            put_be32(pb, (file_size-aiff->ssnd-12)/enc->block_align);
    
            /* Sound Data chunk size */
            url_fseek(pb, aiff->ssnd, SEEK_SET);
            put_be32(pb, file_size - aiff->ssnd - 4);
    
            /* return to the end */
            url_fseek(pb, end_size, SEEK_SET);
    
            put_flush_packet(pb);
        }
    
        return 0;
    }
    
    AVOutputFormat aiff_muxer = {
        "aiff",
        NULL_IF_CONFIG_SMALL("Audio IFF"),
        "audio/aiff",
        "aif,aiff,afc,aifc",
        sizeof(AIFFOutputContext),
        CODEC_ID_PCM_S16BE,
        CODEC_ID_NONE,
        aiff_write_header,
        aiff_write_packet,
        aiff_write_trailer,
        .codec_tag= (const AVCodecTag* const []){ff_codec_aiff_tags, 0},
    };