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![Josh Allmann](/assets/img/avatar_default.png)
Patch by Josh Allmann, joshua dot allmann at gmail Originally committed as revision 24798 to svn://svn.ffmpeg.org/ffmpeg/trunk
154 lines
4.4 KiB
C
154 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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*
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* This file is part of FFmpeg.
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*
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* FFmpeg 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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* FFmpeg 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 FFmpeg; 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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* ( http://www.webmproject.org/code/specs/rtp/ )
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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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ByteIOContext *data;
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uint32_t timestamp;
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int is_keyframe;
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};
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static void prepare_packet(AVPacket *pkt, PayloadContext *vp8, int stream)
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{
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av_init_packet(pkt);
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pkt->stream_index = stream;
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pkt->flags = vp8->is_keyframe ? AV_PKT_FLAG_KEY : 0;
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pkt->size = url_close_dyn_buf(vp8->data, &pkt->data);
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pkt->destruct = av_destruct_packet;
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vp8->data = NULL;
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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_packet, end_packet, has_au, ret = AVERROR(EAGAIN);
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if (!buf) {
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// only called when vp8_handle_packet returns 1
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if (!vp8->data) {
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av_log(ctx, AV_LOG_ERROR, "Invalid VP8 data passed\n");
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return AVERROR_INVALIDDATA;
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}
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prepare_packet(pkt, vp8, st->index);
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*timestamp = vp8->timestamp;
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return 0;
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}
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start_packet = *buf & 1;
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end_packet = flags & RTP_FLAG_MARKER;
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has_au = *buf & 2;
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buf++;
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len--;
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if (start_packet) {
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int res;
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uint32_t ts = *timestamp;
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if (vp8->data) {
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// missing end marker; return old frame anyway. untested
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prepare_packet(pkt, vp8, st->index);
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*timestamp = vp8->timestamp; // reset timestamp from old frame
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// if current frame fits into one rtp packet, need to hold
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// that for the next av_get_packet call
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ret = end_packet ? 1 : 0;
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}
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if ((res = url_open_dyn_buf(&vp8->data)) < 0)
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return res;
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vp8->is_keyframe = *buf & 1;
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vp8->timestamp = ts;
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}
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if (!vp8->data || vp8->timestamp != *timestamp && ret == AVERROR(EAGAIN)) {
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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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// cycle through VP8AU headers if needed
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// not tested with actual VP8AUs
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while (len) {
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int au_len = len;
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if (has_au && len > 2) {
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au_len = AV_RB16(buf);
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buf += 2;
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len -= 2;
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if (buf + au_len > buf + len) {
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av_log(ctx, AV_LOG_ERROR, "Invalid VP8AU length\n");
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return AVERROR_INVALIDDATA;
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}
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}
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put_buffer(vp8->data, buf, au_len);
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buf += au_len;
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len -= au_len;
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}
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if (ret != AVERROR(EAGAIN)) // did we miss a end marker?
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return ret;
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if (end_packet) {
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prepare_packet(pkt, vp8, st->index);
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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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av_log(NULL, AV_LOG_WARNING, "RTP VP8 payload is still experimental\n");
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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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url_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 = CODEC_ID_VP8,
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.open = vp8_new_context,
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.close = vp8_free_context,
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.parse_packet = vp8_handle_packet,
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};
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