/* * RTP VP8 Depacketizer * Copyright (c) 2010 Josh Allmann * Copyright (c) 2012 Martin Storsjo * * This file is part of Libav. * * Libav 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. * * Libav 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 Libav; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ /** * @file * @brief RTP support for the VP8 payload * @author Josh Allmann <joshua.allmann@gmail.com> * @see http://tools.ietf.org/html/draft-ietf-payload-vp8-05 */ #include "libavcodec/bytestream.h" #include "rtpdec_formats.h" struct PayloadContext { AVIOContext *data; uint32_t timestamp; }; static int vp8_handle_packet(AVFormatContext *ctx, PayloadContext *vp8, AVStream *st, AVPacket *pkt, uint32_t *timestamp, const uint8_t *buf, int len, int flags) { int start_partition, end_packet; int extended_bits, part_id; int pictureid_present = 0, tl0picidx_present = 0, tid_present = 0, keyidx_present = 0; if (len < 1) return AVERROR_INVALIDDATA; extended_bits = buf[0] & 0x80; start_partition = buf[0] & 0x10; part_id = buf[0] & 0x0f; end_packet = flags & RTP_FLAG_MARKER; buf++; len--; if (extended_bits) { if (len < 1) return AVERROR_INVALIDDATA; pictureid_present = buf[0] & 0x80; tl0picidx_present = buf[0] & 0x40; tid_present = buf[0] & 0x20; keyidx_present = buf[0] & 0x10; buf++; len--; } if (pictureid_present) { int size; if (len < 1) return AVERROR_INVALIDDATA; size = buf[0] & 0x80 ? 2 : 1; buf += size; len -= size; } if (tl0picidx_present) { // Ignoring temporal level zero index buf++; len--; } if (tid_present || keyidx_present) { // Ignoring temporal layer index, layer sync bit and keyframe index buf++; len--; } if (len < 1) return AVERROR_INVALIDDATA; if (start_partition && part_id == 0) { int res; if (vp8->data) { uint8_t *tmp; avio_close_dyn_buf(vp8->data, &tmp); av_free(tmp); vp8->data = NULL; } if ((res = avio_open_dyn_buf(&vp8->data)) < 0) return res; vp8->timestamp = *timestamp; } if (!vp8->data || vp8->timestamp != *timestamp) { av_log(ctx, AV_LOG_WARNING, "Received no start marker; dropping frame\n"); return AVERROR(EAGAIN); } avio_write(vp8->data, buf, len); if (end_packet) { int ret = ff_rtp_finalize_packet(pkt, &vp8->data, st->index); if (ret < 0) return ret; return 0; } return AVERROR(EAGAIN); } static PayloadContext *vp8_new_context(void) { return av_mallocz(sizeof(PayloadContext)); } static void vp8_free_context(PayloadContext *vp8) { if (vp8->data) { uint8_t *tmp; avio_close_dyn_buf(vp8->data, &tmp); av_free(tmp); } av_free(vp8); } RTPDynamicProtocolHandler ff_vp8_dynamic_handler = { .enc_name = "VP8", .codec_type = AVMEDIA_TYPE_VIDEO, .codec_id = AV_CODEC_ID_VP8, .alloc = vp8_new_context, .free = vp8_free_context, .parse_packet = vp8_handle_packet, };