libavformat/rtpdec_svq3.c

   1 /*
   2  * Sorenson-3 (SVQ3/SV3V) payload for RTP
   3  * Copyright (c) 2010 Ronald S. Bultje
   4  *
   5  * This file is part of Libav.
   6  *
   7  * Libav 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  * Libav 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 Libav; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21
  22 /**
  23  * @file
  24  * @brief RTP support for the SV3V (SVQ3) payload
  25  * @author Ronald S. Bultje <rbultje@ronald.bitfreak.net>
  26  * @see http://wiki.multimedia.cx/index.php?title=Sorenson_Video_3#Packetization
  27  */
  28
  29 #include <string.h>
  30 #include "libavutil/intreadwrite.h"
  31 #include "rtp.h"
  32 #include "rtpdec.h"
  33 #include "rtpdec_formats.h"
  34
  35 struct PayloadContext {
  36     AVIOContext *pktbuf;
  37     int64_t        timestamp;
  38 };
  39
  40 /** return 0 on packet, <0 on partial packet or error... */
  41 static int svq3_parse_packet (AVFormatContext *s, PayloadContext *sv,
  42                               AVStream *st, AVPacket *pkt,
  43                               uint32_t *timestamp,
  44                               const uint8_t *buf, int len, uint16_t seq,
  45                               int flags)
  46 {
  47     int config_packet, start_packet, end_packet;
  48
  49     if (len < 2)
  50         return AVERROR_INVALIDDATA;
  51
  52     config_packet = buf[0] & 0x40;
  53     start_packet  = buf[0] & 0x20;
  54     end_packet    = buf[0] & 0x10;
  55     buf += 2;     // ignore buf[1]
  56     len -= 2;
  57
  58     if (config_packet) {
  59
  60         av_freep(&st->codec->extradata);
  61         st->codec->extradata_size = 0;
  62
  63         if (len < 2 || !(st->codec->extradata =
  64                          av_malloc(len + 8 + FF_INPUT_BUFFER_PADDING_SIZE)))
  65             return AVERROR_INVALIDDATA;
  66
  67         st->codec->extradata_size = len + 8;
  68         memcpy(st->codec->extradata, "SEQH", 4);
  69         AV_WB32(st->codec->extradata + 4, len);
  70         memcpy(st->codec->extradata + 8, buf, len);
  71
  72         /* We set codec_id to AV_CODEC_ID_NONE initially to
  73          * delay decoder initialization since extradata is
  74          * carried within the RTP stream, not SDP. Here,
  75          * by setting codec_id to AV_CODEC_ID_SVQ3, we are signalling
  76          * to the decoder that it is OK to initialize. */
  77         st->codec->codec_id = AV_CODEC_ID_SVQ3;
  78
  79         return AVERROR(EAGAIN);
  80     }
  81
  82     if (start_packet) {
  83         int res;
  84
  85         if (sv->pktbuf) {
  86             uint8_t *tmp;
  87             avio_close_dyn_buf(sv->pktbuf, &tmp);
  88             av_free(tmp);
  89         }
  90         if ((res = avio_open_dyn_buf(&sv->pktbuf)) < 0)
  91             return res;
  92         sv->timestamp   = *timestamp;
  93     }
  94
  95     if (!sv->pktbuf)
  96         return AVERROR_INVALIDDATA;
  97
  98     avio_write(sv->pktbuf, buf, len);
  99
 100     if (end_packet) {
 101         int ret = ff_rtp_finalize_packet(pkt, &sv->pktbuf, st->index);
 102         if (ret < 0)
 103             return ret;
 104
 105         *timestamp        = sv->timestamp;
 106         return 0;
 107     }
 108
 109     return AVERROR(EAGAIN);
 110 }
 111
 112 static PayloadContext *svq3_extradata_new(void)
 113 {
 114     return av_mallocz(sizeof(PayloadContext));
 115 }
 116
 117 static void svq3_extradata_free(PayloadContext *sv)
 118 {
 119     if (sv->pktbuf) {
 120         uint8_t *buf;
 121         avio_close_dyn_buf(sv->pktbuf, &buf);
 122         av_free(buf);
 123     }
 124     av_free(sv);
 125 }
 126
 127 RTPDynamicProtocolHandler ff_svq3_dynamic_handler = {
 128     .enc_name         = "X-SV3V-ES",
 129     .codec_type       = AVMEDIA_TYPE_VIDEO,
 130     .codec_id         = AV_CODEC_ID_NONE,      // see if (config_packet) above
 131     .alloc            = svq3_extradata_new,
 132     .free             = svq3_extradata_free,
 133     .parse_packet     = svq3_parse_packet,
 134 };