libavformat/oggenc.c

   1 /*
   2  * Ogg muxer
   3  * Copyright (c) 2007 Baptiste Coudurier <baptiste dot coudurier at free dot fr>
   4  *
   5  * This file is part of FFmpeg.
   6  *
   7  * FFmpeg is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * FFmpeg is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with FFmpeg; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21
  22 #include "libavutil/crc.h"
  23 #include "libavcodec/xiph.h"
  24 #include "libavcodec/bytestream.h"
  25 #include "libavcodec/flac.h"
  26 #include "avformat.h"
  27 #include "internal.h"
  28
  29 typedef struct {
  30     int64_t duration;
  31     unsigned page_counter;
  32     uint8_t *header[3];
  33     int header_len[3];
  34     /** for theora granule */
  35     int kfgshift;
  36     int64_t last_kf_pts;
  37     int vrev;
  38     int eos;
  39 } OGGStreamContext;
  40
  41 static void ogg_update_checksum(AVFormatContext *s, int64_t crc_offset)
  42 {
  43     int64_t pos = url_ftell(s->pb);
  44     uint32_t checksum = get_checksum(s->pb);
  45     url_fseek(s->pb, crc_offset, SEEK_SET);
  46     put_be32(s->pb, checksum);
  47     url_fseek(s->pb, pos, SEEK_SET);
  48 }
  49
  50 static int ogg_write_page(AVFormatContext *s, const uint8_t *data, int size,
  51                           int64_t granule, int stream_index, int flags)
  52 {
  53     OGGStreamContext *oggstream = s->streams[stream_index]->priv_data;
  54     int64_t crc_offset;
  55     int page_segments, i;
  56
  57     if (size >= 255*255) {
  58         granule = -1;
  59         size = 255*255;
  60     } else if (oggstream->eos)
  61         flags |= 4;
  62
  63     page_segments = FFMIN((size/255)+!!size, 255);
  64
  65     init_checksum(s->pb, ff_crc04C11DB7_update, 0);
  66     put_tag(s->pb, "OggS");
  67     put_byte(s->pb, 0);
  68     put_byte(s->pb, flags);
  69     put_le64(s->pb, granule);
  70     put_le32(s->pb, stream_index);
  71     put_le32(s->pb, oggstream->page_counter++);
  72     crc_offset = url_ftell(s->pb);
  73     put_le32(s->pb, 0); // crc
  74     put_byte(s->pb, page_segments);
  75     for (i = 0; i < page_segments-1; i++)
  76         put_byte(s->pb, 255);
  77     if (size) {
  78         put_byte(s->pb, size - (page_segments-1)*255);
  79         put_buffer(s->pb, data, size);
  80     }
  81     ogg_update_checksum(s, crc_offset);
  82     put_flush_packet(s->pb);
  83     return size;
  84 }
  85
  86 static int ogg_build_flac_headers(AVCodecContext *avctx,
  87                                   OGGStreamContext *oggstream, int bitexact)
  88 {
  89     const char *vendor = bitexact ? "ffmpeg" : LIBAVFORMAT_IDENT;
  90     enum FLACExtradataFormat format;
  91     uint8_t *streaminfo;
  92     uint8_t *p;
  93
  94     if (!ff_flac_is_extradata_valid(avctx, &format, &streaminfo))
  95         return -1;
  96
  97     // first packet: STREAMINFO
  98     oggstream->header_len[0] = 51;
  99     oggstream->header[0] = av_mallocz(51); // per ogg flac specs
 100     p = oggstream->header[0];
 101     if (!p)
 102         return AVERROR_NOMEM;
 103     bytestream_put_byte(&p, 0x7F);
 104     bytestream_put_buffer(&p, "FLAC", 4);
 105     bytestream_put_byte(&p, 1); // major version
 106     bytestream_put_byte(&p, 0); // minor version
 107     bytestream_put_be16(&p, 1); // headers packets without this one
 108     bytestream_put_buffer(&p, "fLaC", 4);
 109     bytestream_put_byte(&p, 0x00); // streaminfo
 110     bytestream_put_be24(&p, 34);
 111     bytestream_put_buffer(&p, streaminfo, FLAC_STREAMINFO_SIZE);
 112
 113     // second packet: VorbisComment
 114     oggstream->header_len[1] = 1+3+4+strlen(vendor)+4;
 115     oggstream->header[1] = av_mallocz(oggstream->header_len[1]);
 116     p = oggstream->header[1];
 117     if (!p)
 118         return AVERROR_NOMEM;
 119     bytestream_put_byte(&p, 0x84); // last metadata block and vorbis comment
 120     bytestream_put_be24(&p, oggstream->header_len[1] - 4);
 121     bytestream_put_le32(&p, strlen(vendor));
 122     bytestream_put_buffer(&p, vendor, strlen(vendor));
 123     bytestream_put_le32(&p, 0); // user comment list length
 124
 125     return 0;
 126 }
 127
 128 static int ogg_write_header(AVFormatContext *s)
 129 {
 130     OGGStreamContext *oggstream;
 131     int i, j;
 132     for (i = 0; i < s->nb_streams; i++) {
 133         AVStream *st = s->streams[i];
 134         if (st->codec->codec_type == CODEC_TYPE_AUDIO)
 135             av_set_pts_info(st, 64, 1, st->codec->sample_rate);
 136         else if (st->codec->codec_type == CODEC_TYPE_VIDEO)
 137             av_set_pts_info(st, 64, st->codec->time_base.num, st->codec->time_base.den);
 138         if (st->codec->codec_id != CODEC_ID_VORBIS &&
 139             st->codec->codec_id != CODEC_ID_THEORA &&
 140             st->codec->codec_id != CODEC_ID_FLAC) {
 141             av_log(s, AV_LOG_ERROR, "Unsupported codec id in stream %d\n", i);
 142             return -1;
 143         }
 144
 145         if (!st->codec->extradata || !st->codec->extradata_size) {
 146             av_log(s, AV_LOG_ERROR, "No extradata present\n");
 147             return -1;
 148         }
 149         oggstream = av_mallocz(sizeof(*oggstream));
 150         st->priv_data = oggstream;
 151         if (st->codec->codec_id == CODEC_ID_FLAC) {
 152             int err = ogg_build_flac_headers(st->codec, oggstream,
 153                                              st->codec->flags & CODEC_FLAG_BITEXACT);
 154             if (err) {
 155                 av_log(s, AV_LOG_ERROR, "Error writing FLAC headers\n");
 156                 av_freep(&st->priv_data);
 157                 return err;
 158             }
 159         } else {
 160             if (ff_split_xiph_headers(st->codec->extradata, st->codec->extradata_size,
 161                                       st->codec->codec_id == CODEC_ID_VORBIS ? 30 : 42,
 162                                       oggstream->header, oggstream->header_len) < 0) {
 163                 av_log(s, AV_LOG_ERROR, "Extradata corrupted\n");
 164                 av_freep(&st->priv_data);
 165                 return -1;
 166             }
 167             if (st->codec->codec_id == CODEC_ID_THEORA) {
 168                 /** KFGSHIFT is the width of the less significant section of the granule position
 169                     The less significant section is the frame count since the last keyframe */
 170                 oggstream->kfgshift = ((oggstream->header[0][40]&3)<<3)|(oggstream->header[0][41]>>5);
 171                 oggstream->vrev = oggstream->header[0][9];
 172                 av_log(s, AV_LOG_DEBUG, "theora kfgshift %d, vrev %d\n",
 173                        oggstream->kfgshift, oggstream->vrev);
 174             }
 175         }
 176     }
 177     for (i = 0; i < 3; i++) {
 178         for (j = 0; j < s->nb_streams; j++) {
 179             AVStream *st = s->streams[j];
 180             OGGStreamContext *oggstream = st->priv_data;
 181             if (oggstream && oggstream->header_len[i]) {
 182                 ogg_write_page(s, oggstream->header[i], oggstream->header_len[i],
 183                                0, st->index, i ? 0 : 2); // bos
 184             }
 185         }
 186     }
 187     return 0;
 188 }
 189
 190 static int ogg_write_packet(AVFormatContext *s, AVPacket *pkt)
 191 {
 192     AVStream *st = s->streams[pkt->stream_index];
 193     OGGStreamContext *oggstream = st->priv_data;
 194     uint8_t *ptr = pkt->data;
 195     int ret, size = pkt->size;
 196     int64_t granule;
 197
 198     if (st->codec->codec_id == CODEC_ID_THEORA) {
 199         int64_t pts = oggstream->vrev < 1 ? pkt->pts : pkt->pts + pkt->duration;
 200         int pframe_count;
 201         if (pkt->flags & PKT_FLAG_KEY)
 202             oggstream->last_kf_pts = pts;
 203         pframe_count = pts - oggstream->last_kf_pts;
 204         // prevent frame count from overflow if key frame flag is not set
 205         if (pframe_count >= (1<<oggstream->kfgshift)) {
 206             oggstream->last_kf_pts += pframe_count;
 207             pframe_count = 0;
 208         }
 209         granule = (oggstream->last_kf_pts<<oggstream->kfgshift) | pframe_count;
 210     } else
 211         granule = pkt->pts + pkt->duration;
 212     oggstream->duration = granule;
 213     do {
 214         ret = ogg_write_page(s, ptr, size, granule, pkt->stream_index, ptr != pkt->data);
 215         ptr  += ret; size -= ret;
 216     } while (size > 0 || ret == 255*255); // need to output a last nil page
 217
 218     return 0;
 219 }
 220
 221 static int ogg_compare_granule(AVFormatContext *s, AVPacket *next, AVPacket *pkt)
 222 {
 223     AVStream *st2 = s->streams[next->stream_index];
 224     AVStream *st  = s->streams[pkt ->stream_index];
 225
 226     int64_t next_granule = av_rescale_q(next->pts + next->duration,
 227                                         st2->time_base, AV_TIME_BASE_Q);
 228     int64_t cur_granule  = av_rescale_q(pkt ->pts + pkt ->duration,
 229                                         st ->time_base, AV_TIME_BASE_Q);
 230     return next_granule > cur_granule;
 231 }
 232
 233 static int ogg_interleave_per_granule(AVFormatContext *s, AVPacket *out, AVPacket *pkt, int flush)
 234 {
 235     AVPacketList *pktl;
 236     int stream_count = 0;
 237     int streams[MAX_STREAMS] = {0};
 238     int interleaved = 0;
 239
 240     if (pkt) {
 241         ff_interleave_add_packet(s, pkt, ogg_compare_granule);
 242     }
 243
 244     pktl = s->packet_buffer;
 245     while (pktl) {
 246         if (streams[pktl->pkt.stream_index] == 0)
 247             stream_count++;
 248         streams[pktl->pkt.stream_index]++;
 249         // need to buffer at least one packet to set eos flag
 250         if (streams[pktl->pkt.stream_index] == 2)
 251             interleaved++;
 252         pktl = pktl->next;
 253     }
 254
 255     if ((s->nb_streams == stream_count && interleaved == stream_count) ||
 256         (flush && stream_count)) {
 257         pktl= s->packet_buffer;
 258         *out= pktl->pkt;
 259         s->packet_buffer = pktl->next;
 260         if (flush && streams[out->stream_index] == 1) {
 261             OGGStreamContext *ogg = s->streams[out->stream_index]->priv_data;
 262             ogg->eos = 1;
 263         }
 264         av_freep(&pktl);
 265         return 1;
 266     } else {
 267         av_init_packet(out);
 268         return 0;
 269     }
 270 }
 271
 272 static int ogg_write_trailer(AVFormatContext *s)
 273 {
 274     int i;
 275     for (i = 0; i < s->nb_streams; i++) {
 276         AVStream *st = s->streams[i];
 277         OGGStreamContext *oggstream = st->priv_data;
 278         if (st->codec->codec_id == CODEC_ID_FLAC) {
 279             av_free(oggstream->header[0]);
 280             av_free(oggstream->header[1]);
 281         }
 282         av_freep(&st->priv_data);
 283     }
 284     return 0;
 285 }
 286
 287 AVOutputFormat ogg_muxer = {
 288     "ogg",
 289     NULL_IF_CONFIG_SMALL("Ogg"),
 290     "application/ogg",
 291     "ogg,ogv",
 292     0,
 293     CODEC_ID_FLAC,
 294     CODEC_ID_THEORA,
 295     ogg_write_header,
 296     ogg_write_packet,
 297     ogg_write_trailer,
 298     .interleave_packet = ogg_interleave_per_granule,
 299 };