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             if (ogg_build_flac_headers(st->codec,
 153                                        oggstream, st->codec->flags & CODEC_FLAG_BITEXACT) < 0) {
 154                 av_log(s, AV_LOG_ERROR, "Extradata corrupted\n");
 155                 av_freep(&st->priv_data);
 156             }
 157         } else {
 158             if (ff_split_xiph_headers(st->codec->extradata, st->codec->extradata_size,
 159                                       st->codec->codec_id == CODEC_ID_VORBIS ? 30 : 42,
 160                                       oggstream->header, oggstream->header_len) < 0) {
 161                 av_log(s, AV_LOG_ERROR, "Extradata corrupted\n");
 162                 av_freep(&st->priv_data);
 163                 return -1;
 164             }
 165             if (st->codec->codec_id == CODEC_ID_THEORA) {
 166                 /** KFGSHIFT is the width of the less significant section of the granule position
 167                     The less significant section is the frame count since the last keyframe */
 168                 oggstream->kfgshift = ((oggstream->header[0][40]&3)<<3)|(oggstream->header[0][41]>>5);
 169                 oggstream->vrev = oggstream->header[0][9];
 170                 av_log(s, AV_LOG_DEBUG, "theora kfgshift %d, vrev %d\n",
 171                        oggstream->kfgshift, oggstream->vrev);
 172             }
 173         }
 174     }
 175     for (i = 0; i < 3; i++) {
 176         for (j = 0; j < s->nb_streams; j++) {
 177             AVStream *st = s->streams[j];
 178             OGGStreamContext *oggstream = st->priv_data;
 179             if (oggstream && oggstream->header_len[i]) {
 180                 ogg_write_page(s, oggstream->header[i], oggstream->header_len[i],
 181                                0, st->index, i ? 0 : 2); // bos
 182             }
 183         }
 184     }
 185     return 0;
 186 }
 187
 188 static int ogg_write_packet(AVFormatContext *s, AVPacket *pkt)
 189 {
 190     AVStream *st = s->streams[pkt->stream_index];
 191     OGGStreamContext *oggstream = st->priv_data;
 192     uint8_t *ptr = pkt->data;
 193     int ret, size = pkt->size;
 194     int64_t granule;
 195
 196     if (st->codec->codec_id == CODEC_ID_THEORA) {
 197         int64_t pts = oggstream->vrev < 1 ? pkt->pts : pkt->pts + pkt->duration;
 198         int pframe_count;
 199         if (pkt->flags & PKT_FLAG_KEY)
 200             oggstream->last_kf_pts = pts;
 201         pframe_count = pts - oggstream->last_kf_pts;
 202         // prevent frame count from overflow if key frame flag is not set
 203         if (pframe_count >= (1<<oggstream->kfgshift)) {
 204             oggstream->last_kf_pts += pframe_count;
 205             pframe_count = 0;
 206         }
 207         granule = (oggstream->last_kf_pts<<oggstream->kfgshift) | pframe_count;
 208     } else
 209         granule = pkt->pts + pkt->duration;
 210     oggstream->duration = granule;
 211     do {
 212         ret = ogg_write_page(s, ptr, size, granule, pkt->stream_index, ptr != pkt->data);
 213         ptr  += ret; size -= ret;
 214     } while (size > 0 || ret == 255*255); // need to output a last nil page
 215
 216     return 0;
 217 }
 218
 219 static int ogg_compare_granule(AVFormatContext *s, AVPacket *next, AVPacket *pkt)
 220 {
 221     AVStream *st2 = s->streams[next->stream_index];
 222     AVStream *st  = s->streams[pkt ->stream_index];
 223
 224     int64_t next_granule = av_rescale_q(next->pts + next->duration,
 225                                         st2->time_base, AV_TIME_BASE_Q);
 226     int64_t cur_granule  = av_rescale_q(pkt ->pts + pkt ->duration,
 227                                         st ->time_base, AV_TIME_BASE_Q);
 228     return next_granule > cur_granule;
 229 }
 230
 231 static int ogg_interleave_per_granule(AVFormatContext *s, AVPacket *out, AVPacket *pkt, int flush)
 232 {
 233     AVPacketList *pktl;
 234     int stream_count = 0;
 235     int streams[MAX_STREAMS] = {0};
 236     int interleaved = 0;
 237
 238     if (pkt) {
 239         ff_interleave_add_packet(s, pkt, ogg_compare_granule);
 240     }
 241
 242     pktl = s->packet_buffer;
 243     while (pktl) {
 244         if (streams[pktl->pkt.stream_index] == 0)
 245             stream_count++;
 246         streams[pktl->pkt.stream_index]++;
 247         // need to buffer at least one packet to set eos flag
 248         if (streams[pktl->pkt.stream_index] == 2)
 249             interleaved++;
 250         pktl = pktl->next;
 251     }
 252
 253     if ((s->nb_streams == stream_count && interleaved == stream_count) ||
 254         (flush && stream_count)) {
 255         pktl= s->packet_buffer;
 256         *out= pktl->pkt;
 257         s->packet_buffer = pktl->next;
 258         if (flush && streams[out->stream_index] == 1) {
 259             OGGStreamContext *ogg = s->streams[out->stream_index]->priv_data;
 260             ogg->eos = 1;
 261         }
 262         av_freep(&pktl);
 263         return 1;
 264     } else {
 265         av_init_packet(out);
 266         return 0;
 267     }
 268 }
 269
 270 static int ogg_write_trailer(AVFormatContext *s)
 271 {
 272     int i;
 273     for (i = 0; i < s->nb_streams; i++) {
 274         AVStream *st = s->streams[i];
 275         OGGStreamContext *oggstream = st->priv_data;
 276         if (st->codec->codec_id == CODEC_ID_FLAC) {
 277             av_free(oggstream->header[0]);
 278             av_free(oggstream->header[1]);
 279         }
 280         av_freep(&st->priv_data);
 281     }
 282     return 0;
 283 }
 284
 285 AVOutputFormat ogg_muxer = {
 286     "ogg",
 287     NULL_IF_CONFIG_SMALL("Ogg"),
 288     "application/ogg",
 289     "ogg,ogv",
 290     0,
 291     CODEC_ID_FLAC,
 292     CODEC_ID_THEORA,
 293     ogg_write_header,
 294     ogg_write_packet,
 295     ogg_write_trailer,
 296     .interleave_packet = ogg_interleave_per_granule,
 297 };