342 lines
11 KiB
C
Executable File
342 lines
11 KiB
C
Executable File
/*
|
|
* RTP parser for VP9 payload format (draft version 02) - experimental
|
|
* Copyright (c) 2015 Thomas Volkert <thomas@homer-conferencing.com>
|
|
*
|
|
* 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
|
|
*/
|
|
|
|
#include "libavutil/intreadwrite.h"
|
|
|
|
#include "avio_internal.h"
|
|
#include "rtpdec_formats.h"
|
|
|
|
#define RTP_VP9_DESC_REQUIRED_SIZE 1
|
|
|
|
struct PayloadContext {
|
|
AVIOContext *buf;
|
|
uint32_t timestamp;
|
|
};
|
|
|
|
static av_cold int vp9_init(AVFormatContext *ctx, int st_index,
|
|
PayloadContext *data)
|
|
{
|
|
av_log(ctx, AV_LOG_WARNING,
|
|
"RTP/VP9 support is still experimental\n");
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int vp9_handle_packet(AVFormatContext *ctx, PayloadContext *rtp_vp9_ctx,
|
|
AVStream *st, AVPacket *pkt, uint32_t *timestamp,
|
|
const uint8_t *buf, int len, uint16_t seq,
|
|
int flags)
|
|
{
|
|
int has_pic_id, has_layer_idc, has_ref_idc, has_ss_data;
|
|
av_unused int pic_id = 0, non_key_frame = 0, inter_picture_layer_frame;
|
|
av_unused int layer_temporal = -1, layer_spatial = -1, layer_quality = -1;
|
|
int ref_fields = 0, has_ref_field_ext_pic_id = 0;
|
|
int first_fragment, last_fragment;
|
|
int rtp_m;
|
|
int res = 0;
|
|
|
|
/* drop data of previous packets in case of non-continuous (lossy) packet stream */
|
|
if (rtp_vp9_ctx->buf && rtp_vp9_ctx->timestamp != *timestamp)
|
|
ffio_free_dyn_buf(&rtp_vp9_ctx->buf);
|
|
|
|
/* sanity check for size of input packet: 1 byte payload at least */
|
|
if (len < RTP_VP9_DESC_REQUIRED_SIZE + 1) {
|
|
av_log(ctx, AV_LOG_ERROR, "Too short RTP/VP9 packet, got %d bytes\n", len);
|
|
return AVERROR_INVALIDDATA;
|
|
}
|
|
|
|
/*
|
|
* decode the required VP9 payload descriptor according to section 4.2 of the spec.:
|
|
*
|
|
* 0 1 2 3 4 5 6 7
|
|
* +-+-+-+-+-+-+-+-+
|
|
* |I|P|L|F|B|E|V|-| (REQUIRED)
|
|
* +-+-+-+-+-+-+-+-+
|
|
*
|
|
* I: PictureID present
|
|
* P: Inter-picture predicted layer frame
|
|
* L: Layer indices present
|
|
* F: Flexible mode
|
|
* B: Start of VP9 frame
|
|
* E: End of picture
|
|
* V: Scalability Structure (SS) present
|
|
*/
|
|
has_pic_id = !!(buf[0] & 0x80);
|
|
inter_picture_layer_frame = !!(buf[0] & 0x40);
|
|
has_layer_idc = !!(buf[0] & 0x20);
|
|
has_ref_idc = !!(buf[0] & 0x10);
|
|
first_fragment = !!(buf[0] & 0x08);
|
|
last_fragment = !!(buf[0] & 0x04);
|
|
has_ss_data = !!(buf[0] & 0x02);
|
|
|
|
rtp_m = !!(flags & RTP_FLAG_MARKER);
|
|
|
|
/* sanity check for markers: B should always be equal to the RTP M marker */
|
|
if (last_fragment != rtp_m) {
|
|
av_log(ctx, AV_LOG_ERROR, "Invalid combination of B and M marker (%d != %d)\n", last_fragment, rtp_m);
|
|
return AVERROR_INVALIDDATA;
|
|
}
|
|
|
|
/* pass the extensions field */
|
|
buf += RTP_VP9_DESC_REQUIRED_SIZE;
|
|
len -= RTP_VP9_DESC_REQUIRED_SIZE;
|
|
|
|
/*
|
|
* decode the 1-byte/2-byte picture ID:
|
|
*
|
|
* 0 1 2 3 4 5 6 7
|
|
* +-+-+-+-+-+-+-+-+
|
|
* I: |M|PICTURE ID | (RECOMMENDED)
|
|
* +-+-+-+-+-+-+-+-+
|
|
* M: | EXTENDED PID | (RECOMMENDED)
|
|
* +-+-+-+-+-+-+-+-+
|
|
*
|
|
* M: The most significant bit of the first octet is an extension flag.
|
|
* PictureID: 8 or 16 bits including the M bit.
|
|
*/
|
|
if (has_pic_id) {
|
|
/* check for 1-byte or 2-byte picture index */
|
|
if (buf[0] & 0x80) {
|
|
if (len < 2) {
|
|
av_log(ctx, AV_LOG_ERROR, "Too short RTP/VP9 packet\n");
|
|
return AVERROR_INVALIDDATA;
|
|
}
|
|
pic_id = AV_RB16(buf) & 0x7fff;
|
|
buf += 2;
|
|
len -= 2;
|
|
} else {
|
|
pic_id = buf[0] & 0x7f;
|
|
buf++;
|
|
len--;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* decode layer indices
|
|
*
|
|
* 0 1 2 3 4 5 6 7
|
|
* +-+-+-+-+-+-+-+-+
|
|
* L: | T | S | Q | R | (CONDITIONALLY RECOMMENDED)
|
|
* +-+-+-+-+-+-+-+-+
|
|
*
|
|
* T, S and Q are 2-bit indices for temporal, spatial, and quality layers.
|
|
* If "F" is set in the initial octet, R is 2 bits representing the number
|
|
* of reference fields this frame refers to.
|
|
*/
|
|
if (has_layer_idc) {
|
|
if (len < 1) {
|
|
av_log(ctx, AV_LOG_ERROR, "Too short RTP/VP9 packet\n");
|
|
return AVERROR_INVALIDDATA;
|
|
}
|
|
layer_temporal = buf[0] & 0xC0;
|
|
layer_spatial = buf[0] & 0x30;
|
|
layer_quality = buf[0] & 0x0C;
|
|
if (has_ref_idc) {
|
|
ref_fields = buf[0] & 0x03;
|
|
if (ref_fields)
|
|
non_key_frame = 1;
|
|
}
|
|
buf++;
|
|
len--;
|
|
}
|
|
|
|
/*
|
|
* decode the reference fields
|
|
*
|
|
* 0 1 2 3 4 5 6 7
|
|
* +-+-+-+-+-+-+-+-+ -\
|
|
* F: | PID |X| RS| RQ| (OPTIONAL) .
|
|
* +-+-+-+-+-+-+-+-+ . - R times
|
|
* X: | EXTENDED PID | (OPTIONAL) .
|
|
* +-+-+-+-+-+-+-+-+ -/
|
|
*
|
|
* PID: The relative Picture ID referred to by this frame.
|
|
* RS and RQ: The spatial and quality layer IDs.
|
|
* X: 1 if this layer index has an extended relative Picture ID.
|
|
*/
|
|
if (has_ref_idc) {
|
|
while (ref_fields) {
|
|
if (len < 1) {
|
|
av_log(ctx, AV_LOG_ERROR, "Too short RTP/VP9 packet\n");
|
|
return AVERROR_INVALIDDATA;
|
|
}
|
|
|
|
has_ref_field_ext_pic_id = buf[0] & 0x10;
|
|
|
|
/* pass ref. field */
|
|
if (has_ref_field_ext_pic_id) {
|
|
if (len < 2) {
|
|
av_log(ctx, AV_LOG_ERROR, "Too short RTP/VP9 packet\n");
|
|
return AVERROR_INVALIDDATA;
|
|
}
|
|
|
|
/* ignore ref. data */
|
|
|
|
buf += 2;
|
|
len -= 2;
|
|
} else {
|
|
|
|
/* ignore ref. data */
|
|
|
|
buf++;
|
|
len--;
|
|
}
|
|
ref_fields--;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* decode the scalability structure (SS)
|
|
*
|
|
* 0 1 2 3 4 5 6 7
|
|
* +-+-+-+-+-+-+-+-+
|
|
* V: | PATTERN LENGTH|
|
|
* +-+-+-+-+-+-+-+-+ -\
|
|
* | T | S | Q | R | (OPTIONAL) .
|
|
* +-+-+-+-+-+-+-+-+ -\ .
|
|
* | PID |X| RS| RQ| (OPTIONAL) . . - PAT. LEN. times
|
|
* +-+-+-+-+-+-+-+-+ . - R times .
|
|
* X: | EXTENDED PID | (OPTIONAL) . .
|
|
* +-+-+-+-+-+-+-+-+ -/ -/
|
|
*
|
|
* PID: The relative Picture ID referred to by this frame.
|
|
* RS and RQ: The spatial and quality layer IDs.
|
|
* X: 1 if this layer index has an extended relative Picture ID.
|
|
*/
|
|
if (has_ss_data) {
|
|
int n_s, y, g, i;
|
|
if (len < 1) {
|
|
av_log(ctx, AV_LOG_ERROR, "Too short RTP/VP9 packet\n");
|
|
return AVERROR_INVALIDDATA;
|
|
}
|
|
n_s = buf[0] >> 5;
|
|
y = !!(buf[0] & 0x10);
|
|
g = !!(buf[0] & 0x08);
|
|
buf++;
|
|
len--;
|
|
if (n_s > 0) {
|
|
avpriv_report_missing_feature(ctx, "VP9 scalability structure with multiple layers");
|
|
return AVERROR_PATCHWELCOME;
|
|
}
|
|
if (y) {
|
|
if (len < 4 * (n_s + 1)) {
|
|
av_log(ctx, AV_LOG_ERROR, "Too short RTP/VP9 packet\n");
|
|
return AVERROR_INVALIDDATA;
|
|
}
|
|
for (i = 0; i < n_s + 1; i++) {
|
|
av_unused int w, h;
|
|
w = AV_RB16(buf);
|
|
h = AV_RB16(buf + 2);
|
|
buf += 4;
|
|
len -= 4;
|
|
}
|
|
}
|
|
if (g) {
|
|
int n_g;
|
|
if (len < 1) {
|
|
av_log(ctx, AV_LOG_ERROR, "Too short RTP/VP9 packet\n");
|
|
return AVERROR_INVALIDDATA;
|
|
}
|
|
n_g = buf[0];
|
|
buf++;
|
|
len--;
|
|
for (i = 0; i < n_g; i++) {
|
|
av_unused int t, u, r, j;
|
|
if (len < 1) {
|
|
av_log(ctx, AV_LOG_ERROR, "Too short RTP/VP9 packet\n");
|
|
return AVERROR_INVALIDDATA;
|
|
}
|
|
t = buf[0] >> 5;
|
|
u = !!(buf[0] & 0x10);
|
|
r = (buf[0] >> 2) & 0x03;
|
|
buf++;
|
|
len--;
|
|
if (len < r) {
|
|
av_log(ctx, AV_LOG_ERROR, "Too short RTP/VP9 packet\n");
|
|
return AVERROR_INVALIDDATA;
|
|
}
|
|
for (j = 0; j < r; j++) {
|
|
av_unused int p_diff = buf[0];
|
|
buf++;
|
|
len--;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* decode the VP9 payload header
|
|
*
|
|
* spec. is tbd
|
|
*/
|
|
//XXX: implement when specified
|
|
|
|
/* sanity check: 1 byte payload as minimum */
|
|
if (len < 1) {
|
|
av_log(ctx, AV_LOG_ERROR, "Too short RTP/VP9 packet\n");
|
|
return AVERROR_INVALIDDATA;
|
|
}
|
|
|
|
/* start frame buffering with new dynamic buffer */
|
|
if (!rtp_vp9_ctx->buf) {
|
|
/* sanity check: a new frame should have started */
|
|
if (first_fragment) {
|
|
res = avio_open_dyn_buf(&rtp_vp9_ctx->buf);
|
|
if (res < 0)
|
|
return res;
|
|
/* update the timestamp in the frame packet with the one from the RTP packet */
|
|
rtp_vp9_ctx->timestamp = *timestamp;
|
|
} else {
|
|
/* frame not started yet, need more packets */
|
|
return AVERROR(EAGAIN);
|
|
}
|
|
}
|
|
|
|
/* write the fragment to the dyn. buffer */
|
|
avio_write(rtp_vp9_ctx->buf, buf, len);
|
|
|
|
/* do we need more fragments? */
|
|
if (!last_fragment)
|
|
return AVERROR(EAGAIN);
|
|
|
|
/* close frame buffering and create resulting A/V packet */
|
|
res = ff_rtp_finalize_packet(pkt, &rtp_vp9_ctx->buf, st->index);
|
|
if (res < 0)
|
|
return res;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void vp9_close_context(PayloadContext *vp9)
|
|
{
|
|
ffio_free_dyn_buf(&vp9->buf);
|
|
}
|
|
|
|
const RTPDynamicProtocolHandler ff_vp9_dynamic_handler = {
|
|
.enc_name = "VP9",
|
|
.codec_type = AVMEDIA_TYPE_VIDEO,
|
|
.codec_id = AV_CODEC_ID_VP9,
|
|
.priv_data_size = sizeof(PayloadContext),
|
|
.init = vp9_init,
|
|
.close = vp9_close_context,
|
|
.parse_packet = vp9_handle_packet
|
|
};
|