From 51291e60052329b438ea26cbf6baf6ce79e44ad5 Mon Sep 17 00:00:00 2001 From: Josh Allmann Date: Mon, 16 Aug 2010 14:23:35 +0000 Subject: Add RTP depacketization of VP8 Patch by Josh Allmann, joshua dot allmann at gmail Originally committed as revision 24798 to svn://svn.ffmpeg.org/ffmpeg/trunk --- libavformat/rtpdec_vp8.c | 153 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 153 insertions(+) create mode 100644 libavformat/rtpdec_vp8.c (limited to 'libavformat/rtpdec_vp8.c') diff --git a/libavformat/rtpdec_vp8.c b/libavformat/rtpdec_vp8.c new file mode 100644 index 0000000000..8de89ff152 --- /dev/null +++ b/libavformat/rtpdec_vp8.c @@ -0,0 +1,153 @@ +/* + * RTP VP8 Depacketizer + * Copyright (c) 2010 Josh Allmann + * + * This file is part of FFmpeg. + * + * FFmpeg 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. + * + * FFmpeg 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 FFmpeg; 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 + * ( http://www.webmproject.org/code/specs/rtp/ ) + */ + +#include "libavcodec/bytestream.h" + +#include "rtpdec_formats.h" + +struct PayloadContext { + ByteIOContext *data; + uint32_t timestamp; + int is_keyframe; +}; + +static void prepare_packet(AVPacket *pkt, PayloadContext *vp8, int stream) +{ + av_init_packet(pkt); + pkt->stream_index = stream; + pkt->flags = vp8->is_keyframe ? AV_PKT_FLAG_KEY : 0; + pkt->size = url_close_dyn_buf(vp8->data, &pkt->data); + pkt->destruct = av_destruct_packet; + vp8->data = NULL; +} + +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_packet, end_packet, has_au, ret = AVERROR(EAGAIN); + + if (!buf) { + // only called when vp8_handle_packet returns 1 + if (!vp8->data) { + av_log(ctx, AV_LOG_ERROR, "Invalid VP8 data passed\n"); + return AVERROR_INVALIDDATA; + } + prepare_packet(pkt, vp8, st->index); + *timestamp = vp8->timestamp; + return 0; + } + + start_packet = *buf & 1; + end_packet = flags & RTP_FLAG_MARKER; + has_au = *buf & 2; + buf++; + len--; + + if (start_packet) { + int res; + uint32_t ts = *timestamp; + if (vp8->data) { + // missing end marker; return old frame anyway. untested + prepare_packet(pkt, vp8, st->index); + *timestamp = vp8->timestamp; // reset timestamp from old frame + + // if current frame fits into one rtp packet, need to hold + // that for the next av_get_packet call + ret = end_packet ? 1 : 0; + } + if ((res = url_open_dyn_buf(&vp8->data)) < 0) + return res; + vp8->is_keyframe = *buf & 1; + vp8->timestamp = ts; + } + + if (!vp8->data || vp8->timestamp != *timestamp && ret == AVERROR(EAGAIN)) { + av_log(ctx, AV_LOG_WARNING, + "Received no start marker; dropping frame\n"); + return AVERROR(EAGAIN); + } + + // cycle through VP8AU headers if needed + // not tested with actual VP8AUs + while (len) { + int au_len = len; + if (has_au && len > 2) { + au_len = AV_RB16(buf); + buf += 2; + len -= 2; + if (buf + au_len > buf + len) { + av_log(ctx, AV_LOG_ERROR, "Invalid VP8AU length\n"); + return AVERROR_INVALIDDATA; + } + } + + put_buffer(vp8->data, buf, au_len); + buf += au_len; + len -= au_len; + } + + if (ret != AVERROR(EAGAIN)) // did we miss a end marker? + return ret; + + if (end_packet) { + prepare_packet(pkt, vp8, st->index); + return 0; + } + + return AVERROR(EAGAIN); +} + +static PayloadContext *vp8_new_context(void) +{ + av_log(NULL, AV_LOG_WARNING, "RTP VP8 payload is still experimental\n"); + return av_mallocz(sizeof(PayloadContext)); +} + +static void vp8_free_context(PayloadContext *vp8) +{ + if (vp8->data) { + uint8_t *tmp; + url_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 = CODEC_ID_VP8, + .open = vp8_new_context, + .close = vp8_free_context, + .parse_packet = vp8_handle_packet, +}; -- cgit v1.2.3