mirror of
https://gitlab.freedesktop.org/gstreamer/gstreamer.git
synced 2024-12-04 23:46:43 +00:00
9ed6ac1f76
Implements gst_vaapi_utils_h26x_write_nal_unit(), which writes NAL unit length and data to a bitwriter. Note that this helper function applies EPB (Emulation Prevention Bytes), since otherwise produced codec_data might be broken when decoder/parser considering EPB, starts parsing. See sections 7.3 and 7.4 of the H264 and H264 specifications, which describes the emulation_prevention_three_byte. https://bugzilla.gnome.org/show_bug.cgi?id=778750 Signed-off-by: Víctor Manuel Jáquez Leal <victorx.jaquez@intel.com>
147 lines
3.7 KiB
C
147 lines
3.7 KiB
C
/*
|
|
* gstvaapiutils_h26x.c - H.26x related utilities
|
|
*
|
|
* Copyright (C) 2011-2014 Intel Corporation
|
|
* Author: Gwenole Beauchesne
|
|
* Copyright (C) 2017 Intel Corporation
|
|
* Author: Hyunjun Ko <zzoon@igalia.com>
|
|
* Author: Mark Thompson <sw@jkqxz.net>
|
|
*
|
|
* This library 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.
|
|
*
|
|
* 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
|
|
* Lesser General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU Lesser General Public
|
|
* License along with this library; if not, write to the Free
|
|
* Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
|
|
* Boston, MA 02110-1301 USA
|
|
*/
|
|
|
|
#include "gstvaapiutils_h26x_priv.h"
|
|
|
|
/* Write an unsigned integer Exp-Golomb-coded syntax element. i.e. ue(v) */
|
|
gboolean
|
|
bs_write_ue (GstBitWriter * bs, guint32 value)
|
|
{
|
|
guint32 size_in_bits = 0;
|
|
guint32 tmp_value = ++value;
|
|
|
|
while (tmp_value) {
|
|
++size_in_bits;
|
|
tmp_value >>= 1;
|
|
}
|
|
if (size_in_bits > 1
|
|
&& !gst_bit_writer_put_bits_uint32 (bs, 0, size_in_bits - 1))
|
|
return FALSE;
|
|
if (!gst_bit_writer_put_bits_uint32 (bs, value, size_in_bits))
|
|
return FALSE;
|
|
return TRUE;
|
|
}
|
|
|
|
/* Write a signed integer Exp-Golomb-coded syntax element. i.e. se(v) */
|
|
gboolean
|
|
bs_write_se (GstBitWriter * bs, gint32 value)
|
|
{
|
|
guint32 new_val;
|
|
|
|
if (value <= 0)
|
|
new_val = -(value << 1);
|
|
else
|
|
new_val = (value << 1) - 1;
|
|
|
|
if (!bs_write_ue (bs, new_val))
|
|
return FALSE;
|
|
return TRUE;
|
|
}
|
|
|
|
/* Copy from src to dst, applying emulation prevention bytes.
|
|
*
|
|
* This is copied from libavcodec written by Mark Thompson
|
|
* <sw@jkqxz.net> from
|
|
* http://git.videolan.org/?p=ffmpeg.git;a=commit;h=2c62fcdf5d617791a653d7957d449f75569eede0
|
|
*/
|
|
static gboolean
|
|
gst_vaapi_utils_h26x_nal_unit_to_byte_stream (guint8 * dst, guint * dst_len,
|
|
guint8 * src, guint src_len)
|
|
{
|
|
guint dp = 0, sp;
|
|
guint zero_run = 0;
|
|
|
|
for (sp = 0; sp < src_len; sp++) {
|
|
if (dp >= *dst_len)
|
|
goto fail;
|
|
if (zero_run < 2) {
|
|
if (src[sp] == 0)
|
|
++zero_run;
|
|
else
|
|
zero_run = 0;
|
|
} else {
|
|
if ((src[sp] & ~3) == 0) {
|
|
/* emulation_prevention_byte: 0x03 */
|
|
dst[dp++] = 3;
|
|
if (dp >= *dst_len)
|
|
goto fail;
|
|
}
|
|
zero_run = src[sp] == 0;
|
|
}
|
|
dst[dp++] = src[sp];
|
|
}
|
|
|
|
*dst_len = dp;
|
|
return TRUE;
|
|
|
|
fail:
|
|
*dst_len = 0;
|
|
return FALSE;
|
|
}
|
|
|
|
/**
|
|
* gst_vaapi_utils_h26x_write_nal_unit:
|
|
* @bs: a #GstBitWriter instance
|
|
* @nal: the NAL (Network Abstraction Layer) unit to write
|
|
* @nal_size: the size, in bytes, of @nal
|
|
*
|
|
* Writes in the @bs the @nal rewritten with the "emulation prevention
|
|
* bytes" if required.
|
|
*
|
|
* Returns: TRUE if the NAL unit could be coded applying the
|
|
* "emulation prevention bytes"; otherwise FALSE.
|
|
**/
|
|
gboolean
|
|
gst_vaapi_utils_h26x_write_nal_unit (GstBitWriter * bs, guint8 * nal,
|
|
guint nal_size)
|
|
{
|
|
guint8 *byte_stream = NULL;
|
|
guint byte_stream_len;
|
|
|
|
byte_stream_len = nal_size + 10;
|
|
byte_stream = g_malloc (byte_stream_len);
|
|
|
|
if (!byte_stream)
|
|
return FALSE;
|
|
|
|
if (!gst_vaapi_utils_h26x_nal_unit_to_byte_stream (byte_stream,
|
|
&byte_stream_len, nal, nal_size)) {
|
|
g_free (byte_stream);
|
|
return FALSE;
|
|
}
|
|
|
|
WRITE_UINT32 (bs, byte_stream_len, 16);
|
|
gst_bit_writer_put_bytes (bs, byte_stream, byte_stream_len);
|
|
g_free (byte_stream);
|
|
|
|
return TRUE;
|
|
|
|
bs_error:
|
|
{
|
|
GST_ERROR ("failed to write codec-data");
|
|
g_free (byte_stream);
|
|
return FALSE;
|
|
}
|
|
}
|