gstreamer/subprojects/gstreamer-vaapi/gst-libs/gst/vaapi/gstvaapiutils_h26x.c

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/*
* 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;
}
}