/*
  * Ogg muxer
  * Copyright (c) 2007 Baptiste Coudurier <baptiste dot coudurier at free dot fr>
  *
  * 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 "libavutil/crc.h"

 #include "libavutil/opt.h"

 #include "libavutil/random_seed.h"

 #include "libavcodec/xiph.h"
 #include "libavcodec/bytestream.h"

 #include "libavcodec/flac.h"

 #include "avformat.h"

 #include "avio_internal.h"

 #include "internal.h"

 #include "vorbiscomment.h"

 #define MAX_PAGE_SIZE 65025
 
 typedef struct {
     int64_t granule;
     int stream_index;
     uint8_t flags;
     uint8_t segments_count;
     uint8_t segments[255];
     uint8_t data[MAX_PAGE_SIZE];
     uint16_t size;
 } OGGPage;
 

 typedef struct {
     unsigned page_counter;
     uint8_t *header[3];
     int header_len[3];
     /** for theora granule */
     int kfgshift;
     int64_t last_kf_pts;
     int vrev;

     int eos;

     unsigned page_count; ///< number of page buffered
     OGGPage page; ///< current page

     unsigned serial_num; ///< serial number

     int64_t last_granule; ///< last packet granule

 } OGGStreamContext;
 

 typedef struct OGGPageList {
     OGGPage page;
     struct OGGPageList *next;
 } OGGPageList;
 
 typedef struct {

     const AVClass *class;

     OGGPageList *page_list;

     int pref_size; ///< preferred page size (0 => fill all segments)

 } OGGContext;
 

 
 static const AVOption options[] = {
     { "oggpagesize", "Set preferred Ogg page size.",
       offsetof(OGGContext, pref_size), FF_OPT_TYPE_INT, 0, 0, MAX_PAGE_SIZE, AV_OPT_FLAG_ENCODING_PARAM},
     { NULL },
 };
 
 static const AVClass ogg_muxer_class = {
     "Ogg muxer",
     av_default_item_name,
     options,
     LIBAVUTIL_VERSION_INT,
 };
 
 

 static void ogg_update_checksum(AVFormatContext *s, AVIOContext *pb, int64_t crc_offset)

 {

     int64_t pos = avio_tell(pb);

     uint32_t checksum = ffio_get_checksum(pb);

     avio_seek(pb, crc_offset, SEEK_SET);

     avio_wb32(pb, checksum);

     avio_seek(pb, pos, SEEK_SET);

 }
 

 static int ogg_write_page(AVFormatContext *s, OGGPage *page, int extra_flags)

 {

     OGGStreamContext *oggstream = s->streams[page->stream_index]->priv_data;

     AVIOContext *pb;

     int64_t crc_offset;

     int ret, size;
     uint8_t *buf;

     ret = avio_open_dyn_buf(&pb);

     if (ret < 0)
         return ret;

     ffio_init_checksum(pb, ff_crc04C11DB7_update, 0);

     ffio_wfourcc(pb, "OggS");

     avio_w8(pb, 0);
     avio_w8(pb, page->flags | extra_flags);
     avio_wl64(pb, page->granule);
     avio_wl32(pb, oggstream->serial_num);
     avio_wl32(pb, oggstream->page_counter++);

     crc_offset = avio_tell(pb);

     avio_wl32(pb, 0); // crc
     avio_w8(pb, page->segments_count);
     avio_write(pb, page->segments, page->segments_count);
     avio_write(pb, page->data, page->size);

 
     ogg_update_checksum(s, pb, crc_offset);

     avio_flush(pb);

     size = avio_close_dyn_buf(pb, &buf);

     if (size < 0)
         return size;
 

     avio_write(s->pb, buf, size);

     avio_flush(s->pb);

     av_free(buf);

     oggstream->page_count--;

     return 0;

 }
 

 static int64_t ogg_granule_to_timestamp(OGGStreamContext *oggstream, int64_t granule)

 {
     if (oggstream->kfgshift)

         return (granule>>oggstream->kfgshift) +
             (granule & ((1<<oggstream->kfgshift)-1));

     else

         return granule;

 }
 
 static int ogg_compare_granule(AVFormatContext *s, OGGPage *next, OGGPage *page)
 {
     AVStream *st2 = s->streams[next->stream_index];
     AVStream *st  = s->streams[page->stream_index];
     int64_t next_granule, cur_granule;
 
     if (next->granule == -1 || page->granule == -1)
         return 0;
 

     next_granule = av_rescale_q(ogg_granule_to_timestamp(st2->priv_data, next->granule),

                                 st2->time_base, AV_TIME_BASE_Q);

     cur_granule  = av_rescale_q(ogg_granule_to_timestamp(st->priv_data, page->granule),

                                 st ->time_base, AV_TIME_BASE_Q);
     return next_granule > cur_granule;
 }
 
 static int ogg_reset_cur_page(OGGStreamContext *oggstream)
 {
     oggstream->page.granule = -1;
     oggstream->page.flags = 0;
     oggstream->page.segments_count = 0;
     oggstream->page.size = 0;
     return 0;
 }
 
 static int ogg_buffer_page(AVFormatContext *s, OGGStreamContext *oggstream)
 {
     OGGContext *ogg = s->priv_data;
     OGGPageList **p = &ogg->page_list;
     OGGPageList *l = av_mallocz(sizeof(*l));
 
     if (!l)
         return AVERROR(ENOMEM);
     l->page = oggstream->page;
 
     oggstream->page_count++;
     ogg_reset_cur_page(oggstream);
 
     while (*p) {
         if (ogg_compare_granule(s, &(*p)->page, &l->page))
             break;
         p = &(*p)->next;
     }
     l->next = *p;
     *p = l;
 
     return 0;
 }
 
 static int ogg_buffer_data(AVFormatContext *s, AVStream *st,
                            uint8_t *data, unsigned size, int64_t granule)
 {
     OGGStreamContext *oggstream = st->priv_data;

     OGGContext *ogg = s->priv_data;

     int total_segments = size / 255 + 1;
     uint8_t *p = data;

     int i, segments, len, flush = 0;
 
     // Handles VFR by flushing page because this frame needs to have a timestamp
     if (st->codec->codec_id == CODEC_ID_THEORA &&
         ogg_granule_to_timestamp(oggstream, granule) >
         ogg_granule_to_timestamp(oggstream, oggstream->last_granule) + 1) {
         if (oggstream->page.granule != -1)
             ogg_buffer_page(s, oggstream);
         flush = 1;
     }

 
     for (i = 0; i < total_segments; ) {
         OGGPage *page = &oggstream->page;
 
         segments = FFMIN(total_segments - i, 255 - page->segments_count);
 
         if (i && !page->segments_count)
             page->flags |= 1; // continued packet
 
         memset(page->segments+page->segments_count, 255, segments - 1);
         page->segments_count += segments - 1;
 
         len = FFMIN(size, segments*255);
         page->segments[page->segments_count++] = len - (segments-1)*255;
         memcpy(page->data+page->size, p, len);
         p += len;
         size -= len;
         i += segments;
         page->size += len;
 
         if (i == total_segments)
             page->granule = granule;
 

         if(page->segments_count == 255 ||
            (ogg->pref_size > 0 && page->size >= ogg->pref_size)) {
            ogg_buffer_page(s, oggstream);

         }
     }

 
     if (flush && oggstream->page.granule != -1)
         ogg_buffer_page(s, oggstream);
 

     return 0;

 }
 

 static uint8_t *ogg_write_vorbiscomment(int offset, int bitexact,

                                         int *header_len, AVDictionary **m, int framing_bit)

 {
     const char *vendor = bitexact ? "ffmpeg" : LIBAVFORMAT_IDENT;
     int size;
     uint8_t *p, *p0;

     unsigned int count;

     ff_metadata_conv(m, ff_vorbiscomment_metadata_conv, NULL);
 

     size = offset + ff_vorbiscomment_length(*m, vendor, &count) + framing_bit;

     p = av_mallocz(size);
     if (!p)
         return NULL;
     p0 = p;
 
     p += offset;

     ff_vorbiscomment_write(&p, m, vendor, count);

     if (framing_bit)
         bytestream_put_byte(&p, 1);

 
     *header_len = size;
     return p0;
 }
 

 static int ogg_build_flac_headers(AVCodecContext *avctx,

                                   OGGStreamContext *oggstream, int bitexact,

                                   AVDictionary **m)

 {

     enum FLACExtradataFormat format;
     uint8_t *streaminfo;

     uint8_t *p;

     if (!ff_flac_is_extradata_valid(avctx, &format, &streaminfo))

         return -1;

 
     // first packet: STREAMINFO

     oggstream->header_len[0] = 51;
     oggstream->header[0] = av_mallocz(51); // per ogg flac specs

     p = oggstream->header[0];

     if (!p)

         return AVERROR(ENOMEM);

     bytestream_put_byte(&p, 0x7F);
     bytestream_put_buffer(&p, "FLAC", 4);
     bytestream_put_byte(&p, 1); // major version
     bytestream_put_byte(&p, 0); // minor version
     bytestream_put_be16(&p, 1); // headers packets without this one
     bytestream_put_buffer(&p, "fLaC", 4);
     bytestream_put_byte(&p, 0x00); // streaminfo
     bytestream_put_be24(&p, 34);

     bytestream_put_buffer(&p, streaminfo, FLAC_STREAMINFO_SIZE);

 
     // second packet: VorbisComment

     p = ogg_write_vorbiscomment(4, bitexact, &oggstream->header_len[1], m, 0);

     if (!p)

         return AVERROR(ENOMEM);

     oggstream->header[1] = p;

     bytestream_put_byte(&p, 0x84); // last metadata block and vorbis comment
     bytestream_put_be24(&p, oggstream->header_len[1] - 4);

 
     return 0;
 }
 
 #define SPEEX_HEADER_SIZE 80
 
 static int ogg_build_speex_headers(AVCodecContext *avctx,

                                    OGGStreamContext *oggstream, int bitexact,

                                    AVDictionary **m)

 {
     uint8_t *p;
 
     if (avctx->extradata_size < SPEEX_HEADER_SIZE)
         return -1;
 
     // first packet: Speex header
     p = av_mallocz(SPEEX_HEADER_SIZE);
     if (!p)

         return AVERROR(ENOMEM);

     oggstream->header[0] = p;
     oggstream->header_len[0] = SPEEX_HEADER_SIZE;
     bytestream_put_buffer(&p, avctx->extradata, SPEEX_HEADER_SIZE);
     AV_WL32(&oggstream->header[0][68], 0);  // set extra_headers to 0
 
     // second packet: VorbisComment

     p = ogg_write_vorbiscomment(0, bitexact, &oggstream->header_len[1], m, 0);

     if (!p)

         return AVERROR(ENOMEM);

     oggstream->header[1] = p;

     return 0;
 }
 
 static int ogg_write_header(AVFormatContext *s)
 {
     OGGStreamContext *oggstream;
     int i, j;

     for (i = 0; i < s->nb_streams; i++) {
         AVStream *st = s->streams[i];

         unsigned serial_num = i;
 

         if (st->codec->codec_type == AVMEDIA_TYPE_AUDIO)

             av_set_pts_info(st, 64, 1, st->codec->sample_rate);

         else if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO)

             av_set_pts_info(st, 64, st->codec->time_base.num, st->codec->time_base.den);
         if (st->codec->codec_id != CODEC_ID_VORBIS &&
             st->codec->codec_id != CODEC_ID_THEORA &&

             st->codec->codec_id != CODEC_ID_SPEEX  &&

             st->codec->codec_id != CODEC_ID_FLAC) {
             av_log(s, AV_LOG_ERROR, "Unsupported codec id in stream %d\n", i);
             return -1;
         }
 
         if (!st->codec->extradata || !st->codec->extradata_size) {
             av_log(s, AV_LOG_ERROR, "No extradata present\n");
             return -1;
         }
         oggstream = av_mallocz(sizeof(*oggstream));

         oggstream->page.stream_index = i;

 
         if (!(st->codec->flags & CODEC_FLAG_BITEXACT))
             do {
                 serial_num = av_get_random_seed();
                 for (j = 0; j < i; j++) {
                     OGGStreamContext *sc = s->streams[j]->priv_data;
                     if (serial_num == sc->serial_num)
                         break;
                 }
             } while (j < i);
         oggstream->serial_num = serial_num;
 

         st->priv_data = oggstream;
         if (st->codec->codec_id == CODEC_ID_FLAC) {

             int err = ogg_build_flac_headers(st->codec, oggstream,

                                              st->codec->flags & CODEC_FLAG_BITEXACT,

                                              &s->metadata);

             if (err) {

                 av_log(s, AV_LOG_ERROR, "Error writing FLAC headers\n");

                 av_freep(&st->priv_data);

                 return err;

             }

         } else if (st->codec->codec_id == CODEC_ID_SPEEX) {
             int err = ogg_build_speex_headers(st->codec, oggstream,

                                               st->codec->flags & CODEC_FLAG_BITEXACT,

                                               &s->metadata);

             if (err) {
                 av_log(s, AV_LOG_ERROR, "Error writing Speex headers\n");
                 av_freep(&st->priv_data);
                 return err;
             }

         } else {

             uint8_t *p;

             const char *cstr = st->codec->codec_id == CODEC_ID_VORBIS ? "vorbis" : "theora";

             int header_type = st->codec->codec_id == CODEC_ID_VORBIS ? 3 : 0x81;
             int framing_bit = st->codec->codec_id == CODEC_ID_VORBIS ? 1 : 0;
 

             if (ff_split_xiph_headers(st->codec->extradata, st->codec->extradata_size,
                                       st->codec->codec_id == CODEC_ID_VORBIS ? 30 : 42,
                                       oggstream->header, oggstream->header_len) < 0) {
                 av_log(s, AV_LOG_ERROR, "Extradata corrupted\n");
                 av_freep(&st->priv_data);
                 return -1;
             }

 
             p = ogg_write_vorbiscomment(7, st->codec->flags & CODEC_FLAG_BITEXACT,

                                         &oggstream->header_len[1], &s->metadata,

                                         framing_bit);
             if (!p)
                 return AVERROR(ENOMEM);
 
             oggstream->header[1] = p;
             bytestream_put_byte(&p, header_type);
             bytestream_put_buffer(&p, cstr, 6);
 

             if (st->codec->codec_id == CODEC_ID_THEORA) {
                 /** KFGSHIFT is the width of the less significant section of the granule position
                     The less significant section is the frame count since the last keyframe */
                 oggstream->kfgshift = ((oggstream->header[0][40]&3)<<3)|(oggstream->header[0][41]>>5);
                 oggstream->vrev = oggstream->header[0][9];
                 av_log(s, AV_LOG_DEBUG, "theora kfgshift %d, vrev %d\n",
                        oggstream->kfgshift, oggstream->vrev);
             }
         }
     }

 
     for (j = 0; j < s->nb_streams; j++) {
         OGGStreamContext *oggstream = s->streams[j]->priv_data;
         ogg_buffer_data(s, s->streams[j], oggstream->header[0],
                         oggstream->header_len[0], 0);
         oggstream->page.flags |= 2; // bos
         ogg_buffer_page(s, oggstream);
     }
     for (j = 0; j < s->nb_streams; j++) {
         AVStream *st = s->streams[j];
         OGGStreamContext *oggstream = st->priv_data;
         for (i = 1; i < 3; i++) {
             if (oggstream && oggstream->header_len[i])
                 ogg_buffer_data(s, st, oggstream->header[i],
                                 oggstream->header_len[i], 0);

         }

         ogg_buffer_page(s, oggstream);

     }
     return 0;
 }
 

 static void ogg_write_pages(AVFormatContext *s, int flush)
 {
     OGGContext *ogg = s->priv_data;
     OGGPageList *next, *p;
 
     if (!ogg->page_list)
         return;
 
     for (p = ogg->page_list; p; ) {
         OGGStreamContext *oggstream =
             s->streams[p->page.stream_index]->priv_data;
         if (oggstream->page_count < 2 && !flush)
             break;
         ogg_write_page(s, &p->page,
                        flush && oggstream->page_count == 1 ? 4 : 0); // eos
         next = p->next;
         av_freep(&p);
         p = next;
     }
     ogg->page_list = p;
 }
 

 static int ogg_write_packet(AVFormatContext *s, AVPacket *pkt)
 {
     AVStream *st = s->streams[pkt->stream_index];
     OGGStreamContext *oggstream = st->priv_data;

     int ret;

     int64_t granule;
 
     if (st->codec->codec_id == CODEC_ID_THEORA) {
         int64_t pts = oggstream->vrev < 1 ? pkt->pts : pkt->pts + pkt->duration;
         int pframe_count;

         if (pkt->flags & AV_PKT_FLAG_KEY)

             oggstream->last_kf_pts = pts;
         pframe_count = pts - oggstream->last_kf_pts;
         // prevent frame count from overflow if key frame flag is not set
         if (pframe_count >= (1<<oggstream->kfgshift)) {
             oggstream->last_kf_pts += pframe_count;
             pframe_count = 0;
         }
         granule = (oggstream->last_kf_pts<<oggstream->kfgshift) | pframe_count;
     } else
         granule = pkt->pts + pkt->duration;
 

     ret = ogg_buffer_data(s, st, pkt->data, pkt->size, granule);
     if (ret < 0)
         return ret;

     ogg_write_pages(s, 0);

     oggstream->last_granule = granule;
 

     return 0;

 }
 

 static int ogg_write_trailer(AVFormatContext *s)

 {

     int i;

     /* flush current page */
     for (i = 0; i < s->nb_streams; i++)
         ogg_buffer_page(s, s->streams[i]->priv_data);

     ogg_write_pages(s, 1);

     for (i = 0; i < s->nb_streams; i++) {
         AVStream *st = s->streams[i];
         OGGStreamContext *oggstream = st->priv_data;

         if (st->codec->codec_id == CODEC_ID_FLAC ||
             st->codec->codec_id == CODEC_ID_SPEEX) {

             av_free(oggstream->header[0]);
             av_free(oggstream->header[1]);
         }
         av_freep(&st->priv_data);
     }
     return 0;
 }
 

 AVOutputFormat ff_ogg_muxer = {

     "ogg",

     NULL_IF_CONFIG_SMALL("Ogg"),

     "application/ogg",

     "ogg,ogv,spx",

     sizeof(OGGContext),

     CODEC_ID_FLAC,
     CODEC_ID_THEORA,
     ogg_write_header,
     ogg_write_packet,
     ogg_write_trailer,

     .priv_class = &ogg_muxer_class,

 };