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ffmpeg / libavformat / oggenc.c @ 95ca3b1e

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/*
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 * Ogg muxer
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 * Copyright (c) 2007 Baptiste Coudurier <baptiste dot coudurier at free dot fr>
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 *
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 * This file is part of FFmpeg.
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 *
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 * FFmpeg is free software; you can redistribute it and/or
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 * modify it under the terms of the GNU Lesser General Public
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 * License as published by the Free Software Foundation; either
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 * version 2.1 of the License, or (at your option) any later version.
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 *
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 * FFmpeg is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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 * Lesser General Public License for more details.
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 *
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 * You should have received a copy of the GNU Lesser General Public
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 * License along with FFmpeg; if not, write to the Free Software
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 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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 */
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#include "libavutil/crc.h"
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#include "libavcodec/xiph.h"
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#include "libavcodec/bytestream.h"
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#include "libavcodec/flac.h"
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#include "avformat.h"
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#include "internal.h"
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#include "vorbiscomment.h"
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#define MAX_PAGE_SIZE 65025
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typedef struct {
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    int64_t granule;
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    int stream_index;
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    uint8_t flags;
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    uint8_t segments_count;
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    uint8_t segments[255];
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    uint8_t data[MAX_PAGE_SIZE];
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    uint16_t size;
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} OGGPage;
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typedef struct {
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    int64_t duration;
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    unsigned page_counter;
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    uint8_t *header[3];
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    int header_len[3];
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    /** for theora granule */
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    int kfgshift;
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    int64_t last_kf_pts;
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    int vrev;
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    int eos;
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    unsigned page_count; ///< number of page buffered
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    OGGPage page; ///< current page
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} OGGStreamContext;
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typedef struct OGGPageList {
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    OGGPage page;
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    struct OGGPageList *next;
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} OGGPageList;
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typedef struct {
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    OGGPageList *page_list;
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} OGGContext;
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static void ogg_update_checksum(AVFormatContext *s, int64_t crc_offset)
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{
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    int64_t pos = url_ftell(s->pb);
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    uint32_t checksum = get_checksum(s->pb);
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    url_fseek(s->pb, crc_offset, SEEK_SET);
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    put_be32(s->pb, checksum);
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    url_fseek(s->pb, pos, SEEK_SET);
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}
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static void ogg_write_page(AVFormatContext *s, OGGPage *page, int extra_flags)
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{
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    OGGStreamContext *oggstream = s->streams[page->stream_index]->priv_data;
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    int64_t crc_offset;
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    init_checksum(s->pb, ff_crc04C11DB7_update, 0);
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    put_tag(s->pb, "OggS");
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    put_byte(s->pb, 0);
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    put_byte(s->pb, page->flags | extra_flags);
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    put_le64(s->pb, page->granule);
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    put_le32(s->pb, page->stream_index);
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    put_le32(s->pb, oggstream->page_counter++);
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    crc_offset = url_ftell(s->pb);
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    put_le32(s->pb, 0); // crc
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    put_byte(s->pb, page->segments_count);
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    put_buffer(s->pb, page->segments, page->segments_count);
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    put_buffer(s->pb, page->data, page->size);
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    ogg_update_checksum(s, crc_offset);
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    put_flush_packet(s->pb);
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    oggstream->page_count--;
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}
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static int64_t ogg_granule_to_timestamp(OGGStreamContext *oggstream, OGGPage *page)
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{
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    if (oggstream->kfgshift)
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        return (page->granule>>oggstream->kfgshift) +
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            (page->granule & ((1<<oggstream->kfgshift)-1));
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    else
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        return page->granule;
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}
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static int ogg_compare_granule(AVFormatContext *s, OGGPage *next, OGGPage *page)
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{
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    AVStream *st2 = s->streams[next->stream_index];
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    AVStream *st  = s->streams[page->stream_index];
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    int64_t next_granule, cur_granule;
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    if (next->granule == -1 || page->granule == -1)
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        return 0;
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    next_granule = av_rescale_q(ogg_granule_to_timestamp(st2->priv_data, next),
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                                st2->time_base, AV_TIME_BASE_Q);
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    cur_granule  = av_rescale_q(ogg_granule_to_timestamp(st->priv_data, page),
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                                st ->time_base, AV_TIME_BASE_Q);
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    return next_granule > cur_granule;
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}
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static int ogg_reset_cur_page(OGGStreamContext *oggstream)
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{
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    oggstream->page.granule = -1;
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    oggstream->page.flags = 0;
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    oggstream->page.segments_count = 0;
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    oggstream->page.size = 0;
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    return 0;
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}
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static int ogg_buffer_page(AVFormatContext *s, OGGStreamContext *oggstream)
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{
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    OGGContext *ogg = s->priv_data;
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    OGGPageList **p = &ogg->page_list;
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    OGGPageList *l = av_mallocz(sizeof(*l));
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    if (!l)
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        return AVERROR(ENOMEM);
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    l->page = oggstream->page;
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    oggstream->page_count++;
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    ogg_reset_cur_page(oggstream);
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    while (*p) {
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        if (ogg_compare_granule(s, &(*p)->page, &l->page))
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            break;
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        p = &(*p)->next;
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    }
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    l->next = *p;
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    *p = l;
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    return 0;
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}
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static int ogg_buffer_data(AVFormatContext *s, AVStream *st,
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                           uint8_t *data, unsigned size, int64_t granule)
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{
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    OGGStreamContext *oggstream = st->priv_data;
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    int total_segments = size / 255 + 1;
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    uint8_t *p = data;
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    int i, segments, len;
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    for (i = 0; i < total_segments; ) {
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        OGGPage *page = &oggstream->page;
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        segments = FFMIN(total_segments - i, 255 - page->segments_count);
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        if (i && !page->segments_count)
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            page->flags |= 1; // continued packet
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        memset(page->segments+page->segments_count, 255, segments - 1);
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        page->segments_count += segments - 1;
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        len = FFMIN(size, segments*255);
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        page->segments[page->segments_count++] = len - (segments-1)*255;
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        memcpy(page->data+page->size, p, len);
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        p += len;
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        size -= len;
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        i += segments;
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        page->size += len;
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        if (i == total_segments)
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            page->granule = granule;
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        if (page->segments_count == 255) {
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            ogg_buffer_page(s, oggstream);
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        }
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    }
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    return 0;
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}
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static uint8_t *ogg_write_vorbiscomment(int offset, int bitexact,
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                                        int *header_len, AVMetadata *m)
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{
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    const char *vendor = bitexact ? "ffmpeg" : LIBAVFORMAT_IDENT;
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    int size;
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    uint8_t *p, *p0;
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    unsigned int count;
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    size = offset + ff_vorbiscomment_length(m, vendor, &count);
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    p = av_mallocz(size);
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    if (!p)
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        return NULL;
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    p0 = p;
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    p += offset;
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    ff_vorbiscomment_write(&p, m, vendor, count);
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    *header_len = size;
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    return p0;
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}
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static int ogg_build_flac_headers(AVCodecContext *avctx,
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                                  OGGStreamContext *oggstream, int bitexact,
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                                  AVMetadata *m)
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{
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    enum FLACExtradataFormat format;
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    uint8_t *streaminfo;
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    uint8_t *p;
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    if (!ff_flac_is_extradata_valid(avctx, &format, &streaminfo))
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        return -1;
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    // first packet: STREAMINFO
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    oggstream->header_len[0] = 51;
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    oggstream->header[0] = av_mallocz(51); // per ogg flac specs
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    p = oggstream->header[0];
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    if (!p)
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        return AVERROR(ENOMEM);
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    bytestream_put_byte(&p, 0x7F);
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    bytestream_put_buffer(&p, "FLAC", 4);
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    bytestream_put_byte(&p, 1); // major version
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    bytestream_put_byte(&p, 0); // minor version
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    bytestream_put_be16(&p, 1); // headers packets without this one
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    bytestream_put_buffer(&p, "fLaC", 4);
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    bytestream_put_byte(&p, 0x00); // streaminfo
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    bytestream_put_be24(&p, 34);
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    bytestream_put_buffer(&p, streaminfo, FLAC_STREAMINFO_SIZE);
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    // second packet: VorbisComment
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    p = ogg_write_vorbiscomment(4, bitexact, &oggstream->header_len[1], m);
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    if (!p)
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        return AVERROR(ENOMEM);
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    oggstream->header[1] = p;
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    bytestream_put_byte(&p, 0x84); // last metadata block and vorbis comment
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    bytestream_put_be24(&p, oggstream->header_len[1] - 4);
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    return 0;
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}
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#define SPEEX_HEADER_SIZE 80
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static int ogg_build_speex_headers(AVCodecContext *avctx,
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                                   OGGStreamContext *oggstream, int bitexact,
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                                   AVMetadata *m)
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{
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    uint8_t *p;
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    if (avctx->extradata_size < SPEEX_HEADER_SIZE)
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        return -1;
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    // first packet: Speex header
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    p = av_mallocz(SPEEX_HEADER_SIZE);
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    if (!p)
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        return AVERROR(ENOMEM);
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    oggstream->header[0] = p;
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    oggstream->header_len[0] = SPEEX_HEADER_SIZE;
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    bytestream_put_buffer(&p, avctx->extradata, SPEEX_HEADER_SIZE);
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    AV_WL32(&oggstream->header[0][68], 0);  // set extra_headers to 0
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    // second packet: VorbisComment
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    p = ogg_write_vorbiscomment(0, bitexact, &oggstream->header_len[1], m);
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    if (!p)
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        return AVERROR(ENOMEM);
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    oggstream->header[1] = p;
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    return 0;
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}
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static int ogg_write_header(AVFormatContext *s)
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{
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    OGGStreamContext *oggstream;
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    int i, j;
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    for (i = 0; i < s->nb_streams; i++) {
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        AVStream *st = s->streams[i];
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        if (st->codec->codec_type == AVMEDIA_TYPE_AUDIO)
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            av_set_pts_info(st, 64, 1, st->codec->sample_rate);
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        else if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO)
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            av_set_pts_info(st, 64, st->codec->time_base.num, st->codec->time_base.den);
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        if (st->codec->codec_id != CODEC_ID_VORBIS &&
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            st->codec->codec_id != CODEC_ID_THEORA &&
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            st->codec->codec_id != CODEC_ID_SPEEX  &&
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            st->codec->codec_id != CODEC_ID_FLAC) {
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            av_log(s, AV_LOG_ERROR, "Unsupported codec id in stream %d\n", i);
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            return -1;
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        }
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        if (!st->codec->extradata || !st->codec->extradata_size) {
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            av_log(s, AV_LOG_ERROR, "No extradata present\n");
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            return -1;
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        }
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        oggstream = av_mallocz(sizeof(*oggstream));
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        oggstream->page.stream_index = i;
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        st->priv_data = oggstream;
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        if (st->codec->codec_id == CODEC_ID_FLAC) {
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            int err = ogg_build_flac_headers(st->codec, oggstream,
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                                             st->codec->flags & CODEC_FLAG_BITEXACT,
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                                             s->metadata);
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            if (err) {
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                av_log(s, AV_LOG_ERROR, "Error writing FLAC headers\n");
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                av_freep(&st->priv_data);
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                return err;
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            }
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        } else if (st->codec->codec_id == CODEC_ID_SPEEX) {
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            int err = ogg_build_speex_headers(st->codec, oggstream,
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                                              st->codec->flags & CODEC_FLAG_BITEXACT,
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                                              s->metadata);
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            if (err) {
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                av_log(s, AV_LOG_ERROR, "Error writing Speex headers\n");
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                av_freep(&st->priv_data);
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                return err;
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            }
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        } else {
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            if (ff_split_xiph_headers(st->codec->extradata, st->codec->extradata_size,
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                                      st->codec->codec_id == CODEC_ID_VORBIS ? 30 : 42,
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                                      oggstream->header, oggstream->header_len) < 0) {
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                av_log(s, AV_LOG_ERROR, "Extradata corrupted\n");
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                av_freep(&st->priv_data);
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                return -1;
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            }
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            if (st->codec->codec_id == CODEC_ID_THEORA) {
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                /** KFGSHIFT is the width of the less significant section of the granule position
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                    The less significant section is the frame count since the last keyframe */
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                oggstream->kfgshift = ((oggstream->header[0][40]&3)<<3)|(oggstream->header[0][41]>>5);
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                oggstream->vrev = oggstream->header[0][9];
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                av_log(s, AV_LOG_DEBUG, "theora kfgshift %d, vrev %d\n",
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                       oggstream->kfgshift, oggstream->vrev);
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            }
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        }
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    }
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    for (j = 0; j < s->nb_streams; j++) {
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        OGGStreamContext *oggstream = s->streams[j]->priv_data;
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        ogg_buffer_data(s, s->streams[j], oggstream->header[0],
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                        oggstream->header_len[0], 0);
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        oggstream->page.flags |= 2; // bos
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        ogg_buffer_page(s, oggstream);
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    }
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    for (j = 0; j < s->nb_streams; j++) {
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        AVStream *st = s->streams[j];
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        OGGStreamContext *oggstream = st->priv_data;
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        for (i = 1; i < 3; i++) {
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            if (oggstream && oggstream->header_len[i])
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                ogg_buffer_data(s, st, oggstream->header[i],
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                                oggstream->header_len[i], 0);
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        }
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        ogg_buffer_page(s, oggstream);
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    }
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    return 0;
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}
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static void ogg_write_pages(AVFormatContext *s, int flush)
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{
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    OGGContext *ogg = s->priv_data;
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    OGGPageList *next, *p;
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367
    if (!ogg->page_list)
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        return;
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    for (p = ogg->page_list; p; ) {
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        OGGStreamContext *oggstream =
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            s->streams[p->page.stream_index]->priv_data;
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        if (oggstream->page_count < 2 && !flush)
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            break;
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        ogg_write_page(s, &p->page,
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                       flush && oggstream->page_count == 1 ? 4 : 0); // eos
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        next = p->next;
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        av_freep(&p);
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        p = next;
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    }
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    ogg->page_list = p;
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}
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static int ogg_write_packet(AVFormatContext *s, AVPacket *pkt)
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{
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    AVStream *st = s->streams[pkt->stream_index];
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    OGGStreamContext *oggstream = st->priv_data;
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    int ret;
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    int64_t granule;
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    if (st->codec->codec_id == CODEC_ID_THEORA) {
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        int64_t pts = oggstream->vrev < 1 ? pkt->pts : pkt->pts + pkt->duration;
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        int pframe_count;
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        if (pkt->flags & AV_PKT_FLAG_KEY)
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            oggstream->last_kf_pts = pts;
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        pframe_count = pts - oggstream->last_kf_pts;
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        // prevent frame count from overflow if key frame flag is not set
398
        if (pframe_count >= (1<<oggstream->kfgshift)) {
399
            oggstream->last_kf_pts += pframe_count;
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            pframe_count = 0;
401
        }
402
        granule = (oggstream->last_kf_pts<<oggstream->kfgshift) | pframe_count;
403
    } else
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        granule = pkt->pts + pkt->duration;
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    oggstream->duration = granule;
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407
    ret = ogg_buffer_data(s, st, pkt->data, pkt->size, granule);
408
    if (ret < 0)
409
        return ret;
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411
    ogg_write_pages(s, 0);
412

    
413
    return 0;
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}
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static int ogg_write_trailer(AVFormatContext *s)
417
{
418
    int i;
419

    
420
    /* flush current page */
421
    for (i = 0; i < s->nb_streams; i++)
422
        ogg_buffer_page(s, s->streams[i]->priv_data);
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424
    ogg_write_pages(s, 1);
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426
    for (i = 0; i < s->nb_streams; i++) {
427
        AVStream *st = s->streams[i];
428
        OGGStreamContext *oggstream = st->priv_data;
429
        if (st->codec->codec_id == CODEC_ID_FLAC ||
430
            st->codec->codec_id == CODEC_ID_SPEEX) {
431
            av_free(oggstream->header[0]);
432
            av_free(oggstream->header[1]);
433
        }
434
        av_freep(&st->priv_data);
435
    }
436
    return 0;
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}
438

    
439
AVOutputFormat ogg_muxer = {
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    "ogg",
441
    NULL_IF_CONFIG_SMALL("Ogg"),
442
    "application/ogg",
443
    "ogg,ogv,spx",
444
    sizeof(OGGContext),
445
    CODEC_ID_FLAC,
446
    CODEC_ID_THEORA,
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    ogg_write_header,
448
    ogg_write_packet,
449
    ogg_write_trailer,
450
    .metadata_conv = ff_vorbiscomment_metadata_conv,
451
};