On 11 August 2010 00:46, Josh Allmann <joshua.allm...@gmail.com> wrote:
> On 4 August 2010 03:32, Luca Barbato <lu_z...@gentoo.org> wrote:
>> On 08/04/2010 09:59 AM, Martin Storsjö wrote:
>>> David, how large is this first data partition approximately? The frames
>>> are fragmented into RTP packets of around ~1450 bytes (usually) - so if
>>> we've got the first packet of a frame but not the rest, would we be better
>>> off returning this than just skipping it?
>>
>> Even better: is there a way to get this information?
>>
>> If is common for every packet/there is a known upper bound, we can pass
>> it through the sdp, or if not we could think about storing the value in
>> an extension header.
>>
>
> Not sure; I'd have to dig through the bitstream spec for this. Ronald,
> do you happen to know off the top of your head?
>
>> Still I guess we could extend the depacketizer interface to get all the
>> standard rtp information as well.
>>
>
> Attached patches should work against the updated VP8 rtp proposal*.
> Also pulled from latest trunk, so they also work with the Xiph stuff.
>
> The depacketizer now supports multiple VP8AUs in one packet but I
> haven't tested that codepath, because VP8AUs are not used by the
> packetizer.
>
> *
> https://groups.google.com/a/webmproject.org/group/webm-discuss/msg/eef6d312ac5c09c3?dmode=source&output=gplain
>
Attaching...
> Josh
>
From b1e3d1fa0dfae7ca89770e1b428f18d90f335345 Mon Sep 17 00:00:00 2001
From: Josh Allmann <joshua.allm...@gmail.com>
Date: Wed, 28 Jul 2010 00:30:09 -0700
Subject: [PATCH 1/2] Add RTP packetization of VP8.
---
libavformat/rtpenc.c | 29 +++++++++++++++++++++++++++++
libavformat/sdp.c | 4 ++++
2 files changed, 33 insertions(+), 0 deletions(-)
diff --git a/libavformat/rtpenc.c b/libavformat/rtpenc.c
index 9335e8c..6caf220 100644
--- a/libavformat/rtpenc.c
+++ b/libavformat/rtpenc.c
@@ -55,6 +55,7 @@ static int is_supported(enum CodecID id)
case CODEC_ID_AMR_WB:
case CODEC_ID_VORBIS:
case CODEC_ID_THEORA:
+ case CODEC_ID_VP8:
return 1;
default:
return 0;
@@ -301,6 +302,31 @@ static void rtp_send_mpegaudio(AVFormatContext *s1,
}
}
+/* Based on a draft spec for VP8 RTP.
+ * (https://groups.google.com/a/webmproject.org/group/webm-discuss/msg/eef6d312ac5c09c3?dmode=source&output=gplain) */
+static void rtp_send_vp8(AVFormatContext *s1, const uint8_t *buf, int size)
+{
+ RTPMuxContext *s = s1->priv_data;
+ int len, max_packet_size;
+
+ s->buf_ptr = s->buf;
+ s->timestamp = s->cur_timestamp;
+ max_packet_size = s->max_payload_size - 1; // minus one for header byte
+
+ *s->buf_ptr++ = 1; // 0b1 indicates start of frame
+ while (size > 0) {
+ len = FFMIN(size, max_packet_size);
+
+ memcpy(s->buf_ptr, buf, len);
+ ff_rtp_send_data(s1, s->buf, len+1, size == len); // marker bit is last packet in frame
+
+ size -= len;
+ buf += len;
+ s->buf_ptr = s->buf;
+ *s->buf_ptr++ = 0; // payload descriptor
+ }
+}
+
static void rtp_send_raw(AVFormatContext *s1,
const uint8_t *buf1, int size)
{
@@ -407,6 +433,9 @@ static int rtp_write_packet(AVFormatContext *s1, AVPacket *pkt)
case CODEC_ID_THEORA:
ff_rtp_send_xiph(s1, pkt->data, size);
break;
+ case CODEC_ID_VP8:
+ rtp_send_vp8(s1, pkt->data, size);
+ break;
default:
/* better than nothing : send the codec raw data */
rtp_send_raw(s1, pkt->data, size);
diff --git a/libavformat/sdp.c b/libavformat/sdp.c
index ab5ef40..ad06906 100644
--- a/libavformat/sdp.c
+++ b/libavformat/sdp.c
@@ -412,6 +412,10 @@ static char *sdp_write_media_attributes(char *buff, int size, AVCodecContext *c,
c->width, c->height, pix_fmt, config);
break;
}
+ case CODEC_ID_VP8:
+ av_strlcatf(buff, size, "a=rtpmap:%d VP8/90000\r\n",
+ payload_type);
+ break;
default:
/* Nothing special to do here... */
break;
--
1.7.0.4
From e011b60502faff08495f78f6a66d96d5c43435c2 Mon Sep 17 00:00:00 2001
From: Josh Allmann <joshua.allm...@gmail.com>
Date: Thu, 29 Jul 2010 03:51:36 -0700
Subject: [PATCH 2/2] Add RTP depacketization of VP8.
---
libavformat/Makefile | 1 +
libavformat/rtpdec.c | 1 +
libavformat/rtpdec_formats.h | 1 +
libavformat/rtpdec_vp8.c | 130 ++++++++++++++++++++++++++++++++++++++++++
4 files changed, 133 insertions(+), 0 deletions(-)
create mode 100644 libavformat/rtpdec_vp8.c
diff --git a/libavformat/Makefile b/libavformat/Makefile
index 16aa0c7..251c463 100644
--- a/libavformat/Makefile
+++ b/libavformat/Makefile
@@ -234,6 +234,7 @@ OBJS-$(CONFIG_SDP_DEMUXER) += rtsp.o \
rtpdec_mpeg4.o \
rtpdec_qdm2.o \
rtpdec_svq3.o \
+ rtpdec_vp8.o \
rtpdec_xiph.o
OBJS-$(CONFIG_SEGAFILM_DEMUXER) += segafilm.o
OBJS-$(CONFIG_SHORTEN_DEMUXER) += raw.o
diff --git a/libavformat/rtpdec.c b/libavformat/rtpdec.c
index c17dc2d..2c5243a 100644
--- a/libavformat/rtpdec.c
+++ b/libavformat/rtpdec.c
@@ -65,6 +65,7 @@ void av_register_rtp_dynamic_payload_handlers(void)
ff_register_dynamic_payload_handler(&ff_theora_dynamic_handler);
ff_register_dynamic_payload_handler(&ff_qdm2_dynamic_handler);
ff_register_dynamic_payload_handler(&ff_svq3_dynamic_handler);
+ ff_register_dynamic_payload_handler(&ff_vp8_dynamic_handler);
ff_register_dynamic_payload_handler(&ff_ms_rtp_asf_pfv_handler);
ff_register_dynamic_payload_handler(&ff_ms_rtp_asf_pfa_handler);
diff --git a/libavformat/rtpdec_formats.h b/libavformat/rtpdec_formats.h
index eac1b52..a96ffa6 100644
--- a/libavformat/rtpdec_formats.h
+++ b/libavformat/rtpdec_formats.h
@@ -44,5 +44,6 @@ extern RTPDynamicProtocolHandler ff_qdm2_dynamic_handler;
extern RTPDynamicProtocolHandler ff_svq3_dynamic_handler;
extern RTPDynamicProtocolHandler ff_theora_dynamic_handler;
extern RTPDynamicProtocolHandler ff_vorbis_dynamic_handler;
+extern RTPDynamicProtocolHandler ff_vp8_dynamic_handler;
#endif /* AVFORMAT_RTPDEC_FORMATS_H */
diff --git a/libavformat/rtpdec_vp8.c b/libavformat/rtpdec_vp8.c
new file mode 100644
index 0000000..0036d77
--- /dev/null
+++ b/libavformat/rtpdec_vp8.c
@@ -0,0 +1,130 @@
+/*
+ * 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 <joshua.allm...@gmail.com>
+ * (https://groups.google.com/a/webmproject.org/group/webm-discuss/msg/eef6d312ac5c09c3?dmode=source&output=gplain)
+ */
+
+#include "libavcodec/bytestream.h"
+
+#include "rtpdec_formats.h"
+
+struct PayloadContext {
+ ByteIOContext *data;
+ uint32_t timestamp;
+ int is_keyframe;
+};
+
+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;
+ if (!buf)
+ return AVERROR_INVALIDDATA;
+
+ start_packet = *buf & 1;
+ end_packet = flags & RTP_FLAG_MARKER;
+ has_au = *buf & 2;
+ buf++;
+ len--;
+
+ if (start_packet) {
+ int res;
+ if (vp8->data) { // drop previous frame if needed
+ uint8_t *tmp;
+ url_close_dyn_buf(vp8->data, &tmp);
+ vp8->data = NULL;
+ av_free(tmp);
+ }
+ if ((res = url_open_dyn_buf(&vp8->data)) < 0)
+ return res;
+ vp8->is_keyframe = *buf & 1;
+ 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);
+ }
+
+ // cycle through VP8AU headers if needed
+ while (len) {
+ int au_len = len;
+ if (has_au && len > 2) {
+ au_len = AV_RB16(buf) & 0x7ff; // use lower 11 bits
+ 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 (end_packet) {
+ av_init_packet(pkt);
+ pkt->stream_index = st->index;
+ 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;
+ 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;
+ 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,
+};
--
1.7.0.4
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