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gstreamer/gst/rtp/gstrtph264depay.c
Thiago Santos a6d73797d0 rtph264depay: prevent trying to get 0 bytes from adapter 
This causes an assertion and would lead to getting a NULL instead
of a buffer. Without proper checking this would easily lead to
a segfault

https://bugzilla.gnome.org/show_bug.cgi?id=737199
2015-02-04 21:37:50 -03:00

1174 lines
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/* GStreamer
* Copyright (C) <2006> Wim Taymans <wim.taymans@gmail.com>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library 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
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#include <stdio.h>
#include <string.h>
#include <gst/base/gstbitreader.h>
#include <gst/rtp/gstrtpbuffer.h>
#include "gstrtph264depay.h"
GST_DEBUG_CATEGORY_STATIC (rtph264depay_debug);
#define GST_CAT_DEFAULT (rtph264depay_debug)
/* This is what we'll default to when downstream hasn't
* expressed a restriction or preference via caps */
#define DEFAULT_BYTE_STREAM TRUE
#define DEFAULT_ACCESS_UNIT FALSE
/* 3 zero bytes syncword */
static const guint8 sync_bytes[] = { 0, 0, 0, 1 };
static GstStaticPadTemplate gst_rtp_h264_depay_src_template =
GST_STATIC_PAD_TEMPLATE ("src",
GST_PAD_SRC,
GST_PAD_ALWAYS,
GST_STATIC_CAPS ("video/x-h264, "
"stream-format = (string) avc, alignment = (string) au; "
"video/x-h264, "
"stream-format = (string) byte-stream, alignment = (string) { nal, au }")
);
static GstStaticPadTemplate gst_rtp_h264_depay_sink_template =
GST_STATIC_PAD_TEMPLATE ("sink",
GST_PAD_SINK,
GST_PAD_ALWAYS,
GST_STATIC_CAPS ("application/x-rtp, "
"media = (string) \"video\", "
"clock-rate = (int) 90000, " "encoding-name = (string) \"H264\"")
/** optional parameters **/
/* "profile-level-id = (string) ANY, " */
/* "max-mbps = (string) ANY, " */
/* "max-fs = (string) ANY, " */
/* "max-cpb = (string) ANY, " */
/* "max-dpb = (string) ANY, " */
/* "max-br = (string) ANY, " */
/* "redundant-pic-cap = (string) { \"0\", \"1\" }, " */
/* "sprop-parameter-sets = (string) ANY, " */
/* "parameter-add = (string) { \"0\", \"1\" }, " */
/* "packetization-mode = (string) { \"0\", \"1\", \"2\" }, " */
/* "sprop-interleaving-depth = (string) ANY, " */
/* "sprop-deint-buf-req = (string) ANY, " */
/* "deint-buf-cap = (string) ANY, " */
/* "sprop-init-buf-time = (string) ANY, " */
/* "sprop-max-don-diff = (string) ANY, " */
/* "max-rcmd-nalu-size = (string) ANY " */
);
#define gst_rtp_h264_depay_parent_class parent_class
G_DEFINE_TYPE (GstRtpH264Depay, gst_rtp_h264_depay,
GST_TYPE_RTP_BASE_DEPAYLOAD);
static void gst_rtp_h264_depay_finalize (GObject * object);
static GstStateChangeReturn gst_rtp_h264_depay_change_state (GstElement *
element, GstStateChange transition);
static GstBuffer *gst_rtp_h264_depay_process (GstRTPBaseDepayload * depayload,
GstBuffer * buf);
static gboolean gst_rtp_h264_depay_setcaps (GstRTPBaseDepayload * filter,
GstCaps * caps);
static gboolean gst_rtp_h264_depay_handle_event (GstRTPBaseDepayload * depay,
GstEvent * event);
static void
gst_rtp_h264_depay_class_init (GstRtpH264DepayClass * klass)
{
GObjectClass *gobject_class;
GstElementClass *gstelement_class;
GstRTPBaseDepayloadClass *gstrtpbasedepayload_class;
gobject_class = (GObjectClass *) klass;
gstelement_class = (GstElementClass *) klass;
gstrtpbasedepayload_class = (GstRTPBaseDepayloadClass *) klass;
gobject_class->finalize = gst_rtp_h264_depay_finalize;
gst_element_class_add_pad_template (gstelement_class,
gst_static_pad_template_get (&gst_rtp_h264_depay_src_template));
gst_element_class_add_pad_template (gstelement_class,
gst_static_pad_template_get (&gst_rtp_h264_depay_sink_template));
gst_element_class_set_static_metadata (gstelement_class,
"RTP H264 depayloader", "Codec/Depayloader/Network/RTP",
"Extracts H264 video from RTP packets (RFC 3984)",
"Wim Taymans <wim.taymans@gmail.com>");
gstelement_class->change_state = gst_rtp_h264_depay_change_state;
gstrtpbasedepayload_class->process = gst_rtp_h264_depay_process;
gstrtpbasedepayload_class->set_caps = gst_rtp_h264_depay_setcaps;
gstrtpbasedepayload_class->handle_event = gst_rtp_h264_depay_handle_event;
}
static void
gst_rtp_h264_depay_init (GstRtpH264Depay * rtph264depay)
{
rtph264depay->adapter = gst_adapter_new ();
rtph264depay->picture_adapter = gst_adapter_new ();
rtph264depay->byte_stream = DEFAULT_BYTE_STREAM;
rtph264depay->merge = DEFAULT_ACCESS_UNIT;
rtph264depay->sps = g_ptr_array_new_with_free_func (
(GDestroyNotify) gst_buffer_unref);
rtph264depay->pps = g_ptr_array_new_with_free_func (
(GDestroyNotify) gst_buffer_unref);
}
static void
gst_rtp_h264_depay_reset (GstRtpH264Depay * rtph264depay)
{
gst_adapter_clear (rtph264depay->adapter);
rtph264depay->wait_start = TRUE;
gst_adapter_clear (rtph264depay->picture_adapter);
rtph264depay->picture_start = FALSE;
rtph264depay->last_keyframe = FALSE;
rtph264depay->last_ts = 0;
rtph264depay->current_fu_type = 0;
rtph264depay->new_codec_data = FALSE;
g_ptr_array_set_size (rtph264depay->sps, 0);
g_ptr_array_set_size (rtph264depay->pps, 0);
}
static void
gst_rtp_h264_depay_finalize (GObject * object)
{
GstRtpH264Depay *rtph264depay;
rtph264depay = GST_RTP_H264_DEPAY (object);
if (rtph264depay->codec_data)
gst_buffer_unref (rtph264depay->codec_data);
g_object_unref (rtph264depay->adapter);
g_object_unref (rtph264depay->picture_adapter);
g_ptr_array_free (rtph264depay->sps, TRUE);
g_ptr_array_free (rtph264depay->pps, TRUE);
G_OBJECT_CLASS (parent_class)->finalize (object);
}
static void
gst_rtp_h264_depay_negotiate (GstRtpH264Depay * rtph264depay)
{
GstCaps *caps;
gint byte_stream = -1;
gint merge = -1;
caps =
gst_pad_get_allowed_caps (GST_RTP_BASE_DEPAYLOAD_SRCPAD (rtph264depay));
GST_DEBUG_OBJECT (rtph264depay, "allowed caps: %" GST_PTR_FORMAT, caps);
if (caps) {
if (gst_caps_get_size (caps) > 0) {
GstStructure *s = gst_caps_get_structure (caps, 0);
const gchar *str = NULL;
if ((str = gst_structure_get_string (s, "stream-format"))) {
if (strcmp (str, "avc") == 0) {
byte_stream = FALSE;
} else if (strcmp (str, "byte-stream") == 0) {
byte_stream = TRUE;
} else {
GST_DEBUG_OBJECT (rtph264depay, "unknown stream-format: %s", str);
}
}
if ((str = gst_structure_get_string (s, "alignment"))) {
if (strcmp (str, "au") == 0) {
merge = TRUE;
} else if (strcmp (str, "nal") == 0) {
merge = FALSE;
} else {
GST_DEBUG_OBJECT (rtph264depay, "unknown alignment: %s", str);
}
}
}
gst_caps_unref (caps);
}
if (byte_stream != -1) {
GST_DEBUG_OBJECT (rtph264depay, "downstream requires byte-stream %d",
byte_stream);
rtph264depay->byte_stream = byte_stream;
} else {
GST_DEBUG_OBJECT (rtph264depay, "defaulting to byte-stream %d",
DEFAULT_BYTE_STREAM);
rtph264depay->byte_stream = DEFAULT_BYTE_STREAM;
}
if (merge != -1) {
GST_DEBUG_OBJECT (rtph264depay, "downstream requires merge %d", merge);
rtph264depay->merge = merge;
} else {
GST_DEBUG_OBJECT (rtph264depay, "defaulting to merge %d",
DEFAULT_ACCESS_UNIT);
rtph264depay->merge = DEFAULT_ACCESS_UNIT;
}
}
/* Stolen from bad/gst/mpegtsdemux/payloader_parsers.c */
/* variable length Exp-Golomb parsing according to H.264 spec 9.1*/
static gboolean
read_golomb (GstBitReader * br, guint32 * value)
{
guint8 b, leading_zeros = -1;
*value = 1;
for (b = 0; !b; leading_zeros++) {
if (!gst_bit_reader_get_bits_uint8 (br, &b, 1))
return FALSE;
*value *= 2;
}
*value = (*value >> 1) - 1;
if (leading_zeros > 0) {
guint32 tmp = 0;
if (!gst_bit_reader_get_bits_uint32 (br, &tmp, leading_zeros))
return FALSE;
*value += tmp;
}
return TRUE;
}
static gboolean
parse_sps (GstMapInfo * map, guint32 * sps_id)
{
GstBitReader br = GST_BIT_READER_INIT (map->data + 4,
map->size - 4);
if (map->size < 5)
return FALSE;
if (!read_golomb (&br, sps_id))
return FALSE;
return TRUE;
}
static gboolean
parse_pps (GstMapInfo * map, guint32 * sps_id, guint32 * pps_id)
{
GstBitReader br = GST_BIT_READER_INIT (map->data + 1,
map->size - 1);
if (map->size < 2)
return FALSE;
if (!read_golomb (&br, pps_id))
return FALSE;
if (!read_golomb (&br, sps_id))
return FALSE;
return TRUE;
}
static gboolean
gst_rtp_h264_set_src_caps (GstRtpH264Depay * rtph264depay)
{
gboolean res;
GstCaps *srccaps;
guchar level = 0;
guchar profile_compat = G_MAXUINT8;
if (!rtph264depay->byte_stream &&
(!rtph264depay->new_codec_data ||
rtph264depay->sps->len == 0 || rtph264depay->pps->len == 0))
return TRUE;
srccaps = gst_caps_new_simple ("video/x-h264",
"stream-format", G_TYPE_STRING,
rtph264depay->byte_stream ? "byte-stream" : "avc",
"alignment", G_TYPE_STRING, rtph264depay->merge ? "au" : "nal", NULL);
if (!rtph264depay->byte_stream) {
GstBuffer *codec_data;
GstMapInfo map;
GstMapInfo nalmap;
guint8 *data;
guint len;
guint new_size;
guint i;
/* start with 7 bytes header */
len = 7;
/* count sps & pps */
for (i = 0; i < rtph264depay->sps->len; i++)
len += 2 + gst_buffer_get_size (g_ptr_array_index (rtph264depay->sps, i));
for (i = 0; i < rtph264depay->pps->len; i++)
len += 2 + gst_buffer_get_size (g_ptr_array_index (rtph264depay->pps, i));
codec_data = gst_buffer_new_and_alloc (len);
g_debug ("alloc_len: %u", len);
gst_buffer_map (codec_data, &map, GST_MAP_READWRITE);
data = map.data;
/* 8 bits version == 1 */
*data++ = 1;
/* According to: ISO/IEC 14496-15:2004(E) section 5.2.4.1
* The level is the max level of all SPSes
* A profile compat bit can only be set if all SPSes include that bit
*/
for (i = 0; i < rtph264depay->sps->len; i++) {
gst_buffer_map (g_ptr_array_index (rtph264depay->sps, i), &nalmap,
GST_MAP_READ);
profile_compat &= nalmap.data[2];
level = MAX (level, nalmap.data[3]);
gst_buffer_unmap (g_ptr_array_index (rtph264depay->sps, i), &nalmap);
}
/* Assume all SPSes use the same profile, so extract from the first SPS */
gst_buffer_map (g_ptr_array_index (rtph264depay->sps, 0), &nalmap,
GST_MAP_READ);
*data++ = nalmap.data[1];
gst_buffer_unmap (g_ptr_array_index (rtph264depay->sps, 0), &nalmap);
*data++ = profile_compat;
*data++ = level;
/* 6 bits reserved | 2 bits lengthSizeMinusOn */
*data++ = 0xff;
/* 3 bits reserved | 5 bits numOfSequenceParameterSets */
*data++ = 0xe0 | (rtph264depay->sps->len & 0x1f);
/* copy all SPS */
for (i = 0; i < rtph264depay->sps->len; i++) {
gst_buffer_map (g_ptr_array_index (rtph264depay->sps, i), &nalmap,
GST_MAP_READ);
GST_DEBUG_OBJECT (rtph264depay, "copy SPS %d of length %u", i,
(guint) nalmap.size);
GST_WRITE_UINT16_BE (data, nalmap.size);
data += 2;
memcpy (data, nalmap.data, nalmap.size);
data += nalmap.size;
gst_buffer_unmap (g_ptr_array_index (rtph264depay->sps, i), &nalmap);
}
/* 8 bits numOfPictureParameterSets */
*data++ = rtph264depay->pps->len;
/* copy all PPS */
for (i = 0; i < rtph264depay->pps->len; i++) {
gst_buffer_map (g_ptr_array_index (rtph264depay->pps, i), &nalmap,
GST_MAP_READ);
GST_DEBUG_OBJECT (rtph264depay, "copy PPS %d of length %u", i,
(guint) nalmap.size);
GST_WRITE_UINT16_BE (data, nalmap.size);
data += 2;
memcpy (data, nalmap.data, nalmap.size);
data += nalmap.size;
gst_buffer_unmap (g_ptr_array_index (rtph264depay->pps, i), &nalmap);
}
new_size = data - map.data;
gst_buffer_unmap (codec_data, &map);
gst_buffer_set_size (codec_data, new_size);
gst_caps_set_simple (srccaps,
"codec_data", GST_TYPE_BUFFER, codec_data, NULL);
gst_buffer_unref (codec_data);
}
res = gst_pad_set_caps (GST_RTP_BASE_DEPAYLOAD_SRCPAD (rtph264depay),
srccaps);
gst_caps_unref (srccaps);
if (res)
rtph264depay->new_codec_data = FALSE;
return res;
}
gboolean
gst_rtp_h264_add_sps_pps (GstElement * rtph264, GPtrArray * sps_array,
GPtrArray * pps_array, GstBuffer * nal)
{
GstMapInfo map;
guchar type;
guint i;
gst_buffer_map (nal, &map, GST_MAP_READ);
type = map.data[0] & 0x1f;
if (type == 7) {
guint32 sps_id;
if (!parse_sps (&map, &sps_id)) {
GST_WARNING_OBJECT (rtph264, "Invalid SPS,"
" can't parse seq_parameter_set_id");
goto drop;
}
for (i = 0; i < sps_array->len; i++) {
GstBuffer *sps = g_ptr_array_index (sps_array, i);
GstMapInfo spsmap;
guint32 tmp_sps_id;
gst_buffer_map (sps, &spsmap, GST_MAP_READ);
parse_sps (&spsmap, &tmp_sps_id);
if (sps_id == tmp_sps_id) {
if (map.size == spsmap.size &&
memcmp (map.data, spsmap.data, spsmap.size) == 0) {
GST_LOG_OBJECT (rtph264, "Unchanged SPS %u, not updating", sps_id);
gst_buffer_unmap (sps, &spsmap);
goto drop;
} else {
gst_buffer_unmap (sps, &spsmap);
g_ptr_array_remove_index_fast (sps_array, i);
g_ptr_array_add (sps_array, nal);
GST_LOG_OBJECT (rtph264, "Modified SPS %u, replacing", sps_id);
goto done;
}
}
gst_buffer_unmap (sps, &spsmap);
}
GST_LOG_OBJECT (rtph264, "Adding new SPS %u", sps_id);
g_ptr_array_add (sps_array, nal);
} else if (type == 8) {
guint32 sps_id;
guint32 pps_id;
if (!parse_pps (&map, &sps_id, &pps_id)) {
GST_WARNING_OBJECT (rtph264, "Invalid PPS,"
" can't parse seq_parameter_set_id or pic_parameter_set_id");
goto drop;
}
for (i = 0; i < pps_array->len; i++) {
GstBuffer *pps = g_ptr_array_index (pps_array, i);
GstMapInfo ppsmap;
guint32 tmp_sps_id;
guint32 tmp_pps_id;
gst_buffer_map (pps, &ppsmap, GST_MAP_READ);
parse_pps (&ppsmap, &tmp_sps_id, &tmp_pps_id);
if (sps_id == tmp_sps_id && pps_id == tmp_pps_id) {
if (map.size == ppsmap.size &&
memcmp (map.data, ppsmap.data, ppsmap.size) == 0) {
GST_LOG_OBJECT (rtph264, "Unchanged PPS %u:%u, not updating", sps_id,
pps_id);
gst_buffer_unmap (pps, &ppsmap);
goto drop;
} else {
gst_buffer_unmap (pps, &ppsmap);
g_ptr_array_remove_index_fast (pps_array, i);
g_ptr_array_add (pps_array, nal);
GST_LOG_OBJECT (rtph264, "Modified PPS %u:%u, replacing",
sps_id, pps_id);
goto done;
}
}
gst_buffer_unmap (pps, &ppsmap);
}
GST_LOG_OBJECT (rtph264, "Adding new PPS %u:%i", sps_id, pps_id);
g_ptr_array_add (pps_array, nal);
} else {
goto drop;
}
done:
gst_buffer_unmap (nal, &map);
return TRUE;
drop:
gst_buffer_unmap (nal, &map);
gst_buffer_unref (nal);
return FALSE;
}
static void
gst_rtp_h264_depay_add_sps_pps (GstRtpH264Depay * rtph264depay, GstBuffer * nal)
{
if (gst_rtp_h264_add_sps_pps (GST_ELEMENT (rtph264depay),
rtph264depay->sps, rtph264depay->pps, nal))
rtph264depay->new_codec_data = TRUE;
}
static gboolean
gst_rtp_h264_depay_setcaps (GstRTPBaseDepayload * depayload, GstCaps * caps)
{
gint clock_rate;
GstStructure *structure = gst_caps_get_structure (caps, 0);
GstRtpH264Depay *rtph264depay;
const gchar *ps;
GstBuffer *codec_data;
GstMapInfo map;
guint8 *ptr;
rtph264depay = GST_RTP_H264_DEPAY (depayload);
if (!gst_structure_get_int (structure, "clock-rate", &clock_rate))
clock_rate = 90000;
depayload->clock_rate = clock_rate;
/* Base64 encoded, comma separated config NALs */
ps = gst_structure_get_string (structure, "sprop-parameter-sets");
/* negotiate with downstream w.r.t. output format and alignment */
gst_rtp_h264_depay_negotiate (rtph264depay);
if (rtph264depay->byte_stream && ps != NULL) {
/* for bytestream we only need the parameter sets but we don't error out
* when they are not there, we assume they are in the stream. */
gchar **params;
guint len, total;
gint i;
params = g_strsplit (ps, ",", 0);
/* count total number of bytes in base64. Also include the sync bytes in
* front of the params. */
len = 0;
for (i = 0; params[i]; i++) {
len += strlen (params[i]);
len += sizeof (sync_bytes);
}
/* we seriously overshoot the length, but it's fine. */
codec_data = gst_buffer_new_and_alloc (len);
gst_buffer_map (codec_data, &map, GST_MAP_WRITE);
ptr = map.data;
total = 0;
for (i = 0; params[i]; i++) {
guint save = 0;
gint state = 0;
GST_DEBUG_OBJECT (depayload, "decoding param %d (%s)", i, params[i]);
memcpy (ptr, sync_bytes, sizeof (sync_bytes));
ptr += sizeof (sync_bytes);
len =
g_base64_decode_step (params[i], strlen (params[i]), ptr, &state,
&save);
GST_DEBUG_OBJECT (depayload, "decoded %d bytes", len);
total += len + sizeof (sync_bytes);
ptr += len;
}
gst_buffer_unmap (codec_data, &map);
gst_buffer_resize (codec_data, 0, total);
g_strfreev (params);
/* keep the codec_data, we need to send it as the first buffer. We cannot
* push it in the adapter because the adapter might be flushed on discont.
*/
if (rtph264depay->codec_data)
gst_buffer_unref (rtph264depay->codec_data);
rtph264depay->codec_data = codec_data;
} else if (!rtph264depay->byte_stream) {
gchar **params;
gint i;
if (ps == NULL)
goto incomplete_caps;
params = g_strsplit (ps, ",", 0);
GST_DEBUG_OBJECT (depayload, "we have %d params", g_strv_length (params));
/* start with 7 bytes header */
for (i = 0; params[i]; i++) {
GstBuffer *nal;
GstMapInfo nalmap;
gsize nal_len;
guint save = 0;
gint state = 0;
nal_len = strlen (params[i]);
nal = gst_buffer_new_and_alloc (nal_len);
gst_buffer_map (nal, &nalmap, GST_MAP_READWRITE);
nal_len =
g_base64_decode_step (params[i], nal_len, nalmap.data, &state, &save);
GST_DEBUG_OBJECT (depayload, "adding param %d as %s", i,
((nalmap.data[0] & 0x1f) == 7) ? "SPS" : "PPS");
gst_buffer_unmap (nal, &nalmap);
gst_buffer_set_size (nal, nal_len);
gst_rtp_h264_depay_add_sps_pps (rtph264depay, nal);
}
g_strfreev (params);
if (rtph264depay->sps->len == 0 || rtph264depay->pps->len == 0)
goto incomplete_caps;
}
return gst_rtp_h264_set_src_caps (rtph264depay);
/* ERRORS */
incomplete_caps:
{
GST_DEBUG_OBJECT (depayload, "we have incomplete caps,"
" doing setcaps later");
return TRUE;
}
}
static GstBuffer *
gst_rtp_h264_complete_au (GstRtpH264Depay * rtph264depay,
GstClockTime * out_timestamp, gboolean * out_keyframe)
{
guint outsize;
GstBuffer *outbuf;
/* we had a picture in the adapter and we completed it */
GST_DEBUG_OBJECT (rtph264depay, "taking completed AU");
outsize = gst_adapter_available (rtph264depay->picture_adapter);
outbuf = gst_adapter_take_buffer (rtph264depay->picture_adapter, outsize);
*out_timestamp = rtph264depay->last_ts;
*out_keyframe = rtph264depay->last_keyframe;
rtph264depay->last_keyframe = FALSE;
rtph264depay->picture_start = FALSE;
return outbuf;
}
/* SPS/PPS/IDR considered key, all others DELTA;
* so downstream waiting for keyframe can pick up at SPS/PPS/IDR */
#define NAL_TYPE_IS_KEY(nt) (((nt) == 5) || ((nt) == 7) || ((nt) == 8))
static GstBuffer *
gst_rtp_h264_depay_handle_nal (GstRtpH264Depay * rtph264depay, GstBuffer * nal,
GstClockTime in_timestamp, gboolean marker)
{
GstRTPBaseDepayload *depayload = GST_RTP_BASE_DEPAYLOAD (rtph264depay);
gint nal_type;
GstMapInfo map;
GstBuffer *outbuf = NULL;
GstClockTime out_timestamp;
gboolean keyframe, out_keyframe;
gst_buffer_map (nal, &map, GST_MAP_READ);
if (G_UNLIKELY (map.size < 5))
goto short_nal;
nal_type = map.data[4] & 0x1f;
GST_DEBUG_OBJECT (rtph264depay, "handle NAL type %d", nal_type);
keyframe = NAL_TYPE_IS_KEY (nal_type);
out_keyframe = keyframe;
out_timestamp = in_timestamp;
if (!rtph264depay->byte_stream) {
if (nal_type == 7 || nal_type == 8) {
gst_rtp_h264_depay_add_sps_pps (rtph264depay,
gst_buffer_copy_region (nal, GST_BUFFER_COPY_ALL,
4, gst_buffer_get_size (nal) - 4));
gst_buffer_unmap (nal, &map);
gst_buffer_unref (nal);
return NULL;
} else if (rtph264depay->sps->len == 0 || rtph264depay->pps->len == 0) {
/* Down push down any buffer in non-bytestream mode if the SPS/PPS haven't
* go through yet
*/
gst_pad_push_event (GST_RTP_BASE_DEPAYLOAD_SINKPAD (depayload),
gst_event_new_custom (GST_EVENT_CUSTOM_UPSTREAM,
gst_structure_new ("GstForceKeyUnit",
"all-headers", G_TYPE_BOOLEAN, TRUE, NULL)));
gst_buffer_unmap (nal, &map);
gst_buffer_unref (nal);
return NULL;
}
if (rtph264depay->new_codec_data &&
rtph264depay->sps->len > 0 && rtph264depay->pps->len > 0)
gst_rtp_h264_set_src_caps (rtph264depay);
}
if (rtph264depay->merge) {
gboolean start = FALSE, complete = FALSE;
/* marker bit isn't mandatory so in the following code we try to guess
* an AU boundary by detecting a new picture start */
if (!marker) {
/* consider a coded slices (IDR or not) to start a picture,
* (so ending the previous one) if first_mb_in_slice == 0
* (non-0 is part of previous one) */
/* NOTE this is not entirely according to Access Unit specs in 7.4.1.2.4,
* but in practice it works in sane cases, needs not much parsing,
* and also works with broken frame_num in NAL (where spec-wise would fail) */
/* FIXME: this code isn't correct for interlaced content as AUs should be
* constructed with pairs of fields and the guess here will just push out
* AUs with a single field in it */
if (nal_type == 1 || nal_type == 2 || nal_type == 5) {
/* we have a picture start */
start = TRUE;
if (map.data[5] & 0x80) {
/* first_mb_in_slice == 0 completes a picture */
complete = TRUE;
}
} else if (nal_type >= 6 && nal_type <= 9) {
/* SEI, SPS, PPS, AU terminate picture */
complete = TRUE;
}
GST_DEBUG_OBJECT (depayload, "start %d, complete %d", start, complete);
if (complete && rtph264depay->picture_start)
outbuf = gst_rtp_h264_complete_au (rtph264depay, &out_timestamp,
&out_keyframe);
}
/* add to adapter */
gst_buffer_unmap (nal, &map);
GST_DEBUG_OBJECT (depayload, "adding NAL to picture adapter");
gst_adapter_push (rtph264depay->picture_adapter, nal);
rtph264depay->last_ts = in_timestamp;
rtph264depay->last_keyframe |= keyframe;
rtph264depay->picture_start |= start;
if (marker)
outbuf = gst_rtp_h264_complete_au (rtph264depay, &out_timestamp,
&out_keyframe);
} else {
/* no merge, output is input nal */
GST_DEBUG_OBJECT (depayload, "using NAL as output");
outbuf = nal;
gst_buffer_unmap (nal, &map);
}
if (outbuf) {
/* prepend codec_data */
if (rtph264depay->codec_data) {
GST_DEBUG_OBJECT (depayload, "prepending codec_data");
outbuf = gst_buffer_append (rtph264depay->codec_data, outbuf);
rtph264depay->codec_data = NULL;
out_keyframe = TRUE;
}
outbuf = gst_buffer_make_writable (outbuf);
GST_BUFFER_TIMESTAMP (outbuf) = out_timestamp;
if (out_keyframe)
GST_BUFFER_FLAG_UNSET (outbuf, GST_BUFFER_FLAG_DELTA_UNIT);
else
GST_BUFFER_FLAG_SET (outbuf, GST_BUFFER_FLAG_DELTA_UNIT);
}
return outbuf;
/* ERRORS */
short_nal:
{
GST_WARNING_OBJECT (depayload, "dropping short NAL");
gst_buffer_unmap (nal, &map);
gst_buffer_unref (nal);
return NULL;
}
}
static GstBuffer *
gst_rtp_h264_push_fragmentation_unit (GstRtpH264Depay * rtph264depay,
gboolean send)
{
guint outsize;
GstMapInfo map;
GstBuffer *outbuf;
outsize = gst_adapter_available (rtph264depay->adapter);
outbuf = gst_adapter_take_buffer (rtph264depay->adapter, outsize);
gst_buffer_map (outbuf, &map, GST_MAP_WRITE);
GST_DEBUG_OBJECT (rtph264depay, "output %d bytes", outsize);
if (rtph264depay->byte_stream) {
memcpy (map.data, sync_bytes, sizeof (sync_bytes));
} else {
outsize -= 4;
map.data[0] = (outsize >> 24);
map.data[1] = (outsize >> 16);
map.data[2] = (outsize >> 8);
map.data[3] = (outsize);
}
gst_buffer_unmap (outbuf, &map);
rtph264depay->current_fu_type = 0;
outbuf = gst_rtp_h264_depay_handle_nal (rtph264depay, outbuf,
rtph264depay->fu_timestamp, rtph264depay->fu_marker);
if (send && outbuf) {
gst_rtp_base_depayload_push (GST_RTP_BASE_DEPAYLOAD (rtph264depay), outbuf);
outbuf = NULL;
}
return outbuf;
}
static GstBuffer *
gst_rtp_h264_depay_process (GstRTPBaseDepayload * depayload, GstBuffer * buf)
{
GstRtpH264Depay *rtph264depay;
GstBuffer *outbuf = NULL;
guint8 nal_unit_type;
GstRTPBuffer rtp = { NULL };
rtph264depay = GST_RTP_H264_DEPAY (depayload);
/* flush remaining data on discont */
if (GST_BUFFER_IS_DISCONT (buf)) {
gst_adapter_clear (rtph264depay->adapter);
rtph264depay->wait_start = TRUE;
rtph264depay->current_fu_type = 0;
}
{
gint payload_len;
guint8 *payload;
guint header_len;
guint8 nal_ref_idc;
GstMapInfo map;
guint outsize, nalu_size;
GstClockTime timestamp;
gboolean marker;
timestamp = GST_BUFFER_TIMESTAMP (buf);
gst_rtp_buffer_map (buf, GST_MAP_READ, &rtp);
payload_len = gst_rtp_buffer_get_payload_len (&rtp);
payload = gst_rtp_buffer_get_payload (&rtp);
marker = gst_rtp_buffer_get_marker (&rtp);
GST_DEBUG_OBJECT (rtph264depay, "receiving %d bytes", payload_len);
if (payload_len == 0)
goto empty_packet;
/* +---------------+
* |0|1|2|3|4|5|6|7|
* +-+-+-+-+-+-+-+-+
* |F|NRI| Type |
* +---------------+
*
* F must be 0.
*/
nal_ref_idc = (payload[0] & 0x60) >> 5;
nal_unit_type = payload[0] & 0x1f;
/* at least one byte header with type */
header_len = 1;
GST_DEBUG_OBJECT (rtph264depay, "NRI %d, Type %d", nal_ref_idc,
nal_unit_type);
/* If FU unit was being processed, but the current nal is of a different
* type. Assume that the remote payloader is buggy (didn't set the end bit
* when the FU ended) and send out what we gathered thusfar */
if (G_UNLIKELY (rtph264depay->current_fu_type != 0 &&
nal_unit_type != rtph264depay->current_fu_type))
gst_rtp_h264_push_fragmentation_unit (rtph264depay, TRUE);
switch (nal_unit_type) {
case 0:
case 30:
case 31:
/* undefined */
goto undefined_type;
case 25:
/* STAP-B Single-time aggregation packet 5.7.1 */
/* 2 byte extra header for DON */
header_len += 2;
/* fallthrough */
case 24:
{
/* strip headers */
payload += header_len;
payload_len -= header_len;
rtph264depay->wait_start = FALSE;
/* STAP-A Single-time aggregation packet 5.7.1 */
while (payload_len > 2) {
/* 1
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | NALU Size |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*/
nalu_size = (payload[0] << 8) | payload[1];
/* dont include nalu_size */
if (nalu_size > (payload_len - 2))
nalu_size = payload_len - 2;
outsize = nalu_size + sizeof (sync_bytes);
outbuf = gst_buffer_new_and_alloc (outsize);
gst_buffer_map (outbuf, &map, GST_MAP_WRITE);
if (rtph264depay->byte_stream) {
memcpy (map.data, sync_bytes, sizeof (sync_bytes));
} else {
map.data[0] = map.data[1] = 0;
map.data[2] = payload[0];
map.data[3] = payload[1];
}
/* strip NALU size */
payload += 2;
payload_len -= 2;
memcpy (map.data + sizeof (sync_bytes), payload, nalu_size);
gst_buffer_unmap (outbuf, &map);
outbuf =
gst_rtp_h264_depay_handle_nal (rtph264depay, outbuf, timestamp,
marker);
if (outbuf)
gst_adapter_push (rtph264depay->adapter, outbuf);
payload += nalu_size;
payload_len -= nalu_size;
}
outsize = gst_adapter_available (rtph264depay->adapter);
if (outsize > 0) {
outbuf = gst_adapter_take_buffer (rtph264depay->adapter, outsize);
outbuf =
gst_rtp_h264_depay_handle_nal (rtph264depay, outbuf, timestamp,
marker);
}
break;
}
case 26:
/* MTAP16 Multi-time aggregation packet 5.7.2 */
header_len = 5;
/* fallthrough, not implemented */
case 27:
/* MTAP24 Multi-time aggregation packet 5.7.2 */
header_len = 6;
goto not_implemented;
break;
case 28:
case 29:
{
/* FU-A Fragmentation unit 5.8 */
/* FU-B Fragmentation unit 5.8 */
gboolean S, E;
/* +---------------+
* |0|1|2|3|4|5|6|7|
* +-+-+-+-+-+-+-+-+
* |S|E|R| Type |
* +---------------+
*
* R is reserved and always 0
*/
S = (payload[1] & 0x80) == 0x80;
E = (payload[1] & 0x40) == 0x40;
GST_DEBUG_OBJECT (rtph264depay, "S %d, E %d", S, E);
if (rtph264depay->wait_start && !S)
goto waiting_start;
if (S) {
/* NAL unit starts here */
guint8 nal_header;
/* If a new FU unit started, while still processing an older one.
* Assume that the remote payloader is buggy (doesn't set the end
* bit) and send out what we've gathered thusfar */
if (G_UNLIKELY (rtph264depay->current_fu_type != 0))
gst_rtp_h264_push_fragmentation_unit (rtph264depay, TRUE);
rtph264depay->current_fu_type = nal_unit_type;
rtph264depay->fu_timestamp = timestamp;
rtph264depay->wait_start = FALSE;
/* reconstruct NAL header */
nal_header = (payload[0] & 0xe0) | (payload[1] & 0x1f);
/* strip type header, keep FU header, we'll reuse it to reconstruct
* the NAL header. */
payload += 1;
payload_len -= 1;
nalu_size = payload_len;
outsize = nalu_size + sizeof (sync_bytes);
outbuf = gst_buffer_new_and_alloc (outsize);
gst_buffer_map (outbuf, &map, GST_MAP_WRITE);
memcpy (map.data + sizeof (sync_bytes), payload, nalu_size);
map.data[sizeof (sync_bytes)] = nal_header;
gst_buffer_unmap (outbuf, &map);
GST_DEBUG_OBJECT (rtph264depay, "queueing %d bytes", outsize);
/* and assemble in the adapter */
gst_adapter_push (rtph264depay->adapter, outbuf);
} else {
/* strip off FU indicator and FU header bytes */
payload += 2;
payload_len -= 2;
outsize = payload_len;
outbuf = gst_buffer_new_and_alloc (outsize);
gst_buffer_fill (outbuf, 0, payload, outsize);
GST_DEBUG_OBJECT (rtph264depay, "queueing %d bytes", outsize);
/* and assemble in the adapter */
gst_adapter_push (rtph264depay->adapter, outbuf);
}
outbuf = NULL;
rtph264depay->fu_marker = marker;
/* if NAL unit ends, flush the adapter */
if (E)
outbuf = gst_rtp_h264_push_fragmentation_unit (rtph264depay, FALSE);
break;
}
default:
{
rtph264depay->wait_start = FALSE;
/* 1-23 NAL unit Single NAL unit packet per H.264 5.6 */
/* the entire payload is the output buffer */
nalu_size = payload_len;
outsize = nalu_size + sizeof (sync_bytes);
outbuf = gst_buffer_new_and_alloc (outsize);
gst_buffer_map (outbuf, &map, GST_MAP_WRITE);
if (rtph264depay->byte_stream) {
memcpy (map.data, sync_bytes, sizeof (sync_bytes));
} else {
map.data[0] = map.data[1] = 0;
map.data[2] = nalu_size >> 8;
map.data[3] = nalu_size & 0xff;
}
memcpy (map.data + sizeof (sync_bytes), payload, nalu_size);
gst_buffer_unmap (outbuf, &map);
outbuf = gst_rtp_h264_depay_handle_nal (rtph264depay, outbuf, timestamp,
marker);
break;
}
}
gst_rtp_buffer_unmap (&rtp);
}
return outbuf;
/* ERRORS */
empty_packet:
{
GST_DEBUG_OBJECT (rtph264depay, "empty packet");
gst_rtp_buffer_unmap (&rtp);
return NULL;
}
undefined_type:
{
GST_ELEMENT_WARNING (rtph264depay, STREAM, DECODE,
(NULL), ("Undefined packet type"));
gst_rtp_buffer_unmap (&rtp);
return NULL;
}
waiting_start:
{
GST_DEBUG_OBJECT (rtph264depay, "waiting for start");
gst_rtp_buffer_unmap (&rtp);
return NULL;
}
not_implemented:
{
GST_ELEMENT_ERROR (rtph264depay, STREAM, FORMAT,
(NULL), ("NAL unit type %d not supported yet", nal_unit_type));
gst_rtp_buffer_unmap (&rtp);
return NULL;
}
}
static gboolean
gst_rtp_h264_depay_handle_event (GstRTPBaseDepayload * depay, GstEvent * event)
{
GstRtpH264Depay *rtph264depay;
rtph264depay = GST_RTP_H264_DEPAY (depay);
switch (GST_EVENT_TYPE (event)) {
case GST_EVENT_FLUSH_STOP:
gst_rtp_h264_depay_reset (rtph264depay);
break;
default:
break;
}
return
GST_RTP_BASE_DEPAYLOAD_CLASS (parent_class)->handle_event (depay, event);
}
static GstStateChangeReturn
gst_rtp_h264_depay_change_state (GstElement * element,
GstStateChange transition)
{
GstRtpH264Depay *rtph264depay;
GstStateChangeReturn ret;
rtph264depay = GST_RTP_H264_DEPAY (element);
switch (transition) {
case GST_STATE_CHANGE_NULL_TO_READY:
break;
case GST_STATE_CHANGE_READY_TO_PAUSED:
gst_rtp_h264_depay_reset (rtph264depay);
break;
default:
break;
}
ret = GST_ELEMENT_CLASS (parent_class)->change_state (element, transition);
switch (transition) {
case GST_STATE_CHANGE_READY_TO_NULL:
break;
default:
break;
}
return ret;
}
gboolean
gst_rtp_h264_depay_plugin_init (GstPlugin * plugin)
{
GST_DEBUG_CATEGORY_INIT (rtph264depay_debug, "rtph264depay", 0,
"H264 Video RTP Depayloader");
return gst_element_register (plugin, "rtph264depay",
GST_RANK_SECONDARY, GST_TYPE_RTP_H264_DEPAY);
}
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