159 lines
4.4 KiB
C
159 lines
4.4 KiB
C
/*
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* RTP VP8 Depacketizer
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* Copyright (c) 2010 Josh Allmann
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* Copyright (c) 2012 Martin Storsjo
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*
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* This file is part of Libav.
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*
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* Libav is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* Libav is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with Libav; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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/**
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* @file
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* @brief RTP support for the VP8 payload
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* @author Josh Allmann <joshua.allmann@gmail.com>
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* @see http://tools.ietf.org/html/draft-ietf-payload-vp8-05
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*/
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#include "libavcodec/bytestream.h"
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#include "rtpdec_formats.h"
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struct PayloadContext {
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AVIOContext *data;
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uint32_t timestamp;
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};
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static int vp8_handle_packet(AVFormatContext *ctx,
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PayloadContext *vp8,
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AVStream *st,
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AVPacket *pkt,
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uint32_t *timestamp,
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const uint8_t *buf,
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int len, int flags)
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{
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int start_partition, end_packet;
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int extended_bits, non_ref, part_id;
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int pictureid_present = 0, tl0picidx_present = 0, tid_present = 0,
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keyidx_present = 0;
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int pictureid = -1, keyidx = -1;
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if (len < 1)
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return AVERROR_INVALIDDATA;
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extended_bits = buf[0] & 0x80;
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non_ref = buf[0] & 0x20;
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start_partition = buf[0] & 0x10;
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part_id = buf[0] & 0x0f;
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end_packet = flags & RTP_FLAG_MARKER;
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buf++;
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len--;
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if (extended_bits) {
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if (len < 1)
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return AVERROR_INVALIDDATA;
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pictureid_present = buf[0] & 0x80;
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tl0picidx_present = buf[0] & 0x40;
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tid_present = buf[0] & 0x20;
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keyidx_present = buf[0] & 0x10;
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buf++;
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len--;
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}
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if (pictureid_present) {
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if (len < 1)
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return AVERROR_INVALIDDATA;
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if (buf[0] & 0x80) {
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if (len < 2)
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return AVERROR_INVALIDDATA;
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pictureid = AV_RB16(buf) & 0x7fff;
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buf += 2;
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len -= 2;
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} else {
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pictureid = buf[0] & 0x7f;
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buf++;
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len--;
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}
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}
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if (tl0picidx_present) {
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// Ignoring temporal level zero index
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buf++;
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len--;
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}
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if (tid_present || keyidx_present) {
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// Ignoring temporal layer index and layer sync bit
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if (len < 1)
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return AVERROR_INVALIDDATA;
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if (keyidx_present)
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keyidx = buf[0] & 0x1f;
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buf++;
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len--;
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}
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if (len < 1)
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return AVERROR_INVALIDDATA;
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if (start_partition && part_id == 0) {
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int res;
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if (vp8->data) {
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uint8_t *tmp;
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avio_close_dyn_buf(vp8->data, &tmp);
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av_free(tmp);
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vp8->data = NULL;
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}
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if ((res = avio_open_dyn_buf(&vp8->data)) < 0)
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return res;
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vp8->timestamp = *timestamp;
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}
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if (!vp8->data || vp8->timestamp != *timestamp) {
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av_log(ctx, AV_LOG_WARNING,
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"Received no start marker; dropping frame\n");
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return AVERROR(EAGAIN);
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}
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avio_write(vp8->data, buf, len);
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if (end_packet) {
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int ret = ff_rtp_finalize_packet(pkt, &vp8->data, st->index);
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if (ret < 0)
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return ret;
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return 0;
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}
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return AVERROR(EAGAIN);
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}
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static PayloadContext *vp8_new_context(void)
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{
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return av_mallocz(sizeof(PayloadContext));
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}
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static void vp8_free_context(PayloadContext *vp8)
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{
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if (vp8->data) {
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uint8_t *tmp;
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avio_close_dyn_buf(vp8->data, &tmp);
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av_free(tmp);
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}
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av_free(vp8);
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}
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RTPDynamicProtocolHandler ff_vp8_dynamic_handler = {
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.enc_name = "VP8",
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.codec_type = AVMEDIA_TYPE_VIDEO,
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.codec_id = AV_CODEC_ID_VP8,
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.alloc = vp8_new_context,
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.free = vp8_free_context,
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.parse_packet = vp8_handle_packet,
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};
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