vorbiscomment.c

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/*
 * VorbisComment writer
 * Copyright (c) 2009 James Darnley
 *
 * 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 "avio.h"
#include "avio_internal.h"
#include "avformat.h"
#include "metadata.h"
#include "vorbiscomment.h"
#include "libavutil/dict.h"
 
/**
 * VorbisComment metadata conversion mapping.
 * from Ogg Vorbis I format specification: comment field and header specification
 * http://xiph.org/vorbis/doc/v-comment.html
 */
const AVMetadataConv ff_vorbiscomment_metadata_conv[] = {
    { "ALBUMARTIST",  "album_artist"  },
    { "TRACKNUMBER",  "track"         },
    { "DISCNUMBER",   "disc"          },
    /* Adapted from <https://picard-docs.musicbrainz.org/en/appendices/tag_mapping.html#disc-subtitle> */
    { "DISCSUBTITLE", "disc_subtitle" },
    { "DESCRIPTION",  "comment"       },
    { 0 }
};
 
int ff_vorbiscomment_length(const AVDictionary *m, const char *vendor_string,
                            AVChapter **chapters, unsigned int nb_chapters)
{
    AVIOContext *avio_buf;
    int ret, len;
 
    ret = ffio_open_null_buf(&avio_buf);
    if (ret < 0)
        return ret;
 
    ret = ff_vorbiscomment_write(avio_buf, m, vendor_string, chapters, nb_chapters);
    len = ffio_close_null_buf(avio_buf);
    if (ret < 0)
        return ret;
 
    return len;
}
 
int ff_vorbiscomment_write(AVIOContext *pb, const AVDictionary *dict,
                           const char *vendor_string,
                           AVChapter **chapters, unsigned int nb_chapters)
{
    size_t vendor_string_length = strlen(vendor_string);
    int cm_count = 0;
    avio_wl32(pb, vendor_string_length);
    avio_write(pb, vendor_string, vendor_string_length);
    /* Vorbis comment only supports 1000 chapters */
    if (nb_chapters > 1000)
        nb_chapters = 1000;
    if (chapters && nb_chapters) {
        for (int i = 0; i < nb_chapters; i++) {
            cm_count += av_dict_count(chapters[i]->metadata) + 1;
        }
    }
    if (dict) {
        int count = av_dict_count(dict) + cm_count;
        const AVDictionaryEntry *tag = NULL;
        avio_wl32(pb, count);
        while ((tag = av_dict_iterate(dict, tag))) {
            int64_t len1 = strlen(tag->key);
            int64_t len2 = strlen(tag->value);
            if (len1+1+len2 > UINT32_MAX)
                return AVERROR(EINVAL);
            avio_wl32(pb, len1 + 1 + len2);
            avio_write(pb, tag->key, len1);
            avio_w8(pb, '=');
            avio_write(pb, tag->value, len2);
        }
        for (int i = 0; i < nb_chapters; i++) {
            AVChapter *chp = chapters[i];
            char chapter_time[64];
            int h, m, s, ms, len;
 
            s  = av_rescale(chp->start, chp->time_base.num, chp->time_base.den);
            h  = s / 3600;
            m  = (s / 60) % 60;
            ms = av_rescale_q(chp->start, chp->time_base, av_make_q(   1, 1000)) % 1000;
            s  = s % 60;
            len = snprintf(chapter_time, sizeof(chapter_time), "CHAPTER%03d=%02d:%02d:%02d.%03d", i, h, m, s, ms);
            avio_wl32(pb, len);
            avio_write(pb, chapter_time, len);
 
            tag = NULL;
            while ((tag = av_dict_iterate(chapters[i]->metadata, tag))) {
                int64_t len1 = !strcmp(tag->key, "title") ? 4 : strlen(tag->key);
                int64_t len2 = strlen(tag->value);
                if (len1+1+len2+10 > UINT32_MAX)
                    return AVERROR(EINVAL);
                avio_wl32(pb, 10 + len1 + 1 + len2);
                avio_write(pb, chapter_time, 10);
                if (!strcmp(tag->key, "title"))
                    avio_write(pb, "NAME", 4);
                else
                    avio_write(pb, tag->key, len1);
                avio_w8(pb, '=');
                avio_write(pb, tag->value, len2);
            }
        }
    } else
        avio_wl32(pb, 0);
    return 0;
}