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libavformat/oggparsespeex.c

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00001 /*
00002       Copyright (C) 2008  Reimar Döffinger
00003 
00004       Permission is hereby granted, free of charge, to any person
00005       obtaining a copy of this software and associated documentation
00006       files (the "Software"), to deal in the Software without
00007       restriction, including without limitation the rights to use, copy,
00008       modify, merge, publish, distribute, sublicense, and/or sell copies
00009       of the Software, and to permit persons to whom the Software is
00010       furnished to do so, subject to the following conditions:
00011 
00012       The above copyright notice and this permission notice shall be
00013       included in all copies or substantial portions of the Software.
00014 
00015       THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
00016       EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
00017       MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
00018       NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
00019       HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
00020       WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
00021       OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
00022       DEALINGS IN THE SOFTWARE.
00023 **/
00024 
00025 #include <stdlib.h>
00026 #include "libavutil/bswap.h"
00027 #include "libavutil/avstring.h"
00028 #include "libavcodec/get_bits.h"
00029 #include "libavcodec/bytestream.h"
00030 #include "avformat.h"
00031 #include "oggdec.h"
00032 
00033 struct speex_params {
00034     int final_packet_duration;
00035     int seq;
00036 };
00037 
00038 static int speex_header(AVFormatContext *s, int idx) {
00039     struct ogg *ogg = s->priv_data;
00040     struct ogg_stream *os = ogg->streams + idx;
00041     struct speex_params *spxp = os->private;
00042     AVStream *st = s->streams[idx];
00043     uint8_t *p = os->buf + os->pstart;
00044 
00045     if (!spxp) {
00046         spxp = av_mallocz(sizeof(*spxp));
00047         os->private = spxp;
00048     }
00049 
00050     if (spxp->seq > 1)
00051         return 0;
00052 
00053     if (spxp->seq == 0) {
00054         int frames_per_packet;
00055         st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
00056         st->codec->codec_id = CODEC_ID_SPEEX;
00057 
00058         st->codec->sample_rate = AV_RL32(p + 36);
00059         st->codec->channels = AV_RL32(p + 48);
00060 
00061         /* We treat the whole Speex packet as a single frame everywhere Speex
00062            is handled in FFmpeg.  This avoids the complexities of splitting
00063            and joining individual Speex frames, which are not always
00064            byte-aligned. */
00065         st->codec->frame_size = AV_RL32(p + 56);
00066         frames_per_packet     = AV_RL32(p + 64);
00067         if (frames_per_packet)
00068             st->codec->frame_size *= frames_per_packet;
00069 
00070         st->codec->extradata_size = os->psize;
00071         st->codec->extradata = av_malloc(st->codec->extradata_size
00072                                          + FF_INPUT_BUFFER_PADDING_SIZE);
00073         memcpy(st->codec->extradata, p, st->codec->extradata_size);
00074 
00075         st->time_base.num = 1;
00076         st->time_base.den = st->codec->sample_rate;
00077     } else
00078         ff_vorbis_comment(s, &st->metadata, p, os->psize);
00079 
00080     spxp->seq++;
00081     return 1;
00082 }
00083 
00084 static int ogg_page_packets(struct ogg_stream *os)
00085 {
00086     int i;
00087     int packets = 0;
00088     for (i = 0; i < os->nsegs; i++)
00089         if (os->segments[i] < 255)
00090             packets++;
00091     return packets;
00092 }
00093 
00094 static int speex_packet(AVFormatContext *s, int idx)
00095 {
00096     struct ogg *ogg = s->priv_data;
00097     struct ogg_stream *os = ogg->streams + idx;
00098     struct speex_params *spxp = os->private;
00099     int packet_size = s->streams[idx]->codec->frame_size;
00100 
00101     if (os->flags & OGG_FLAG_EOS && os->lastpts != AV_NOPTS_VALUE &&
00102         os->granule > 0) {
00103         /* first packet of final page. we have to calculate the final packet
00104            duration here because it is the only place we know the next-to-last
00105            granule position. */
00106         spxp->final_packet_duration = os->granule - os->lastpts -
00107                                       packet_size * (ogg_page_packets(os) - 1);
00108     }
00109 
00110     if (!os->lastpts && os->granule > 0)
00111         /* first packet */
00112         os->pduration = os->granule - packet_size * (ogg_page_packets(os) - 1);
00113     else if (os->flags & OGG_FLAG_EOS && os->segp == os->nsegs &&
00114              spxp->final_packet_duration)
00115         /* final packet */
00116         os->pduration = spxp->final_packet_duration;
00117     else
00118         os->pduration = packet_size;
00119 
00120     return 0;
00121 }
00122 
00123 const struct ogg_codec ff_speex_codec = {
00124     .magic = "Speex   ",
00125     .magicsize = 8,
00126     .header = speex_header,
00127     .packet = speex_packet
00128 };

Generated on Fri Sep 16 2011 17:17:50 for FFmpeg by  doxygen 1.7.1