mirror of
https://gitlab.freedesktop.org/gstreamer/gstreamer.git
synced 2024-09-08 13:18:52 +00:00
We not only want to create a NAL gstmemory, but also need to create and get the raw data of a NAL writer for the later usage. Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/1051>
570 lines
13 KiB
C
570 lines
13 KiB
C
/* Gstreamer
|
|
* Copyright (C) <2011> Intel Corporation
|
|
* Copyright (C) <2011> Collabora Ltd.
|
|
* Copyright (C) <2011> Thibault Saunier <thibault.saunier@collabora.com>
|
|
*
|
|
* Some bits C-c,C-v'ed and s/4/3 from h264parse and videoparsers/h264parse.c:
|
|
* Copyright (C) <2010> Mark Nauwelaerts <mark.nauwelaerts@collabora.co.uk>
|
|
* Copyright (C) <2010> Collabora Multimedia
|
|
* Copyright (C) <2010> Nokia Corporation
|
|
*
|
|
* (C) 2005 Michal Benes <michal.benes@itonis.tv>
|
|
* (C) 2008 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.
|
|
*/
|
|
|
|
/*
|
|
* Common code for NAL parsing from h264 and h265 parsers.
|
|
*/
|
|
|
|
#ifdef HAVE_CONFIG_H
|
|
# include "config.h"
|
|
#endif
|
|
|
|
#include "nalutils.h"
|
|
#include <string.h>
|
|
|
|
/* Compute Ceil(Log2(v)) */
|
|
/* Derived from branchless code for integer log2(v) from:
|
|
<http://graphics.stanford.edu/~seander/bithacks.html#IntegerLog> */
|
|
guint
|
|
ceil_log2 (guint32 v)
|
|
{
|
|
guint r, shift;
|
|
|
|
v--;
|
|
r = (v > 0xFFFF) << 4;
|
|
v >>= r;
|
|
shift = (v > 0xFF) << 3;
|
|
v >>= shift;
|
|
r |= shift;
|
|
shift = (v > 0xF) << 2;
|
|
v >>= shift;
|
|
r |= shift;
|
|
shift = (v > 0x3) << 1;
|
|
v >>= shift;
|
|
r |= shift;
|
|
r |= (v >> 1);
|
|
return r + 1;
|
|
}
|
|
|
|
/****** Nal parser ******/
|
|
|
|
void
|
|
nal_reader_init (NalReader * nr, const guint8 * data, guint size)
|
|
{
|
|
nr->data = data;
|
|
nr->size = size;
|
|
nr->n_epb = 0;
|
|
|
|
nr->byte = 0;
|
|
nr->bits_in_cache = 0;
|
|
/* fill with something other than 0 to detect emulation prevention bytes */
|
|
nr->first_byte = 0xff;
|
|
nr->epb_cache = 0xff;
|
|
nr->cache = 0xff;
|
|
}
|
|
|
|
gboolean
|
|
nal_reader_read (NalReader * nr, guint nbits)
|
|
{
|
|
if (G_UNLIKELY (nr->byte * 8 + (nbits - nr->bits_in_cache) > nr->size * 8)) {
|
|
GST_DEBUG ("Can not read %u bits, bits in cache %u, Byte * 8 %u, size in "
|
|
"bits %u", nbits, nr->bits_in_cache, nr->byte * 8, nr->size * 8);
|
|
return FALSE;
|
|
}
|
|
|
|
while (nr->bits_in_cache < nbits) {
|
|
guint8 byte;
|
|
|
|
next_byte:
|
|
if (G_UNLIKELY (nr->byte >= nr->size))
|
|
return FALSE;
|
|
|
|
byte = nr->data[nr->byte++];
|
|
nr->epb_cache = (nr->epb_cache << 8) | byte;
|
|
|
|
/* check if the byte is a emulation_prevention_three_byte */
|
|
if ((nr->epb_cache & 0xffffff) == 0x3) {
|
|
nr->n_epb++;
|
|
goto next_byte;
|
|
}
|
|
nr->cache = (nr->cache << 8) | nr->first_byte;
|
|
nr->first_byte = byte;
|
|
nr->bits_in_cache += 8;
|
|
}
|
|
|
|
return TRUE;
|
|
}
|
|
|
|
/* Skips the specified amount of bits. This is only suitable to a
|
|
cacheable number of bits */
|
|
gboolean
|
|
nal_reader_skip (NalReader * nr, guint nbits)
|
|
{
|
|
g_assert (nbits <= 8 * sizeof (nr->cache));
|
|
|
|
if (G_UNLIKELY (!nal_reader_read (nr, nbits)))
|
|
return FALSE;
|
|
|
|
nr->bits_in_cache -= nbits;
|
|
|
|
return TRUE;
|
|
}
|
|
|
|
/* Generic version to skip any number of bits */
|
|
gboolean
|
|
nal_reader_skip_long (NalReader * nr, guint nbits)
|
|
{
|
|
/* Leave out enough bits in the cache once we are finished */
|
|
const guint skip_size = 4 * sizeof (nr->cache);
|
|
guint remaining = nbits;
|
|
|
|
nbits %= skip_size;
|
|
while (remaining > 0) {
|
|
if (!nal_reader_skip (nr, nbits))
|
|
return FALSE;
|
|
remaining -= nbits;
|
|
nbits = skip_size;
|
|
}
|
|
return TRUE;
|
|
}
|
|
|
|
guint
|
|
nal_reader_get_pos (const NalReader * nr)
|
|
{
|
|
return nr->byte * 8 - nr->bits_in_cache;
|
|
}
|
|
|
|
guint
|
|
nal_reader_get_remaining (const NalReader * nr)
|
|
{
|
|
return (nr->size - nr->byte) * 8 + nr->bits_in_cache;
|
|
}
|
|
|
|
guint
|
|
nal_reader_get_epb_count (const NalReader * nr)
|
|
{
|
|
return nr->n_epb;
|
|
}
|
|
|
|
#define NAL_READER_READ_BITS(bits) \
|
|
gboolean \
|
|
nal_reader_get_bits_uint##bits (NalReader *nr, guint##bits *val, guint nbits) \
|
|
{ \
|
|
guint shift; \
|
|
\
|
|
if (!nal_reader_read (nr, nbits)) \
|
|
return FALSE; \
|
|
\
|
|
/* bring the required bits down and truncate */ \
|
|
shift = nr->bits_in_cache - nbits; \
|
|
*val = nr->first_byte >> shift; \
|
|
\
|
|
*val |= nr->cache << (8 - shift); \
|
|
/* mask out required bits */ \
|
|
if (nbits < bits) \
|
|
*val &= ((guint##bits)1 << nbits) - 1; \
|
|
\
|
|
nr->bits_in_cache = shift; \
|
|
\
|
|
return TRUE; \
|
|
} \
|
|
|
|
NAL_READER_READ_BITS (8);
|
|
NAL_READER_READ_BITS (16);
|
|
NAL_READER_READ_BITS (32);
|
|
|
|
#define NAL_READER_PEEK_BITS(bits) \
|
|
gboolean \
|
|
nal_reader_peek_bits_uint##bits (const NalReader *nr, guint##bits *val, guint nbits) \
|
|
{ \
|
|
NalReader tmp; \
|
|
\
|
|
tmp = *nr; \
|
|
return nal_reader_get_bits_uint##bits (&tmp, val, nbits); \
|
|
}
|
|
|
|
NAL_READER_PEEK_BITS (8);
|
|
|
|
gboolean
|
|
nal_reader_get_ue (NalReader * nr, guint32 * val)
|
|
{
|
|
guint i = 0;
|
|
guint8 bit;
|
|
guint32 value;
|
|
|
|
if (G_UNLIKELY (!nal_reader_get_bits_uint8 (nr, &bit, 1)))
|
|
return FALSE;
|
|
|
|
while (bit == 0) {
|
|
i++;
|
|
if (G_UNLIKELY (!nal_reader_get_bits_uint8 (nr, &bit, 1)))
|
|
return FALSE;
|
|
}
|
|
|
|
if (G_UNLIKELY (i > 31))
|
|
return FALSE;
|
|
|
|
if (G_UNLIKELY (!nal_reader_get_bits_uint32 (nr, &value, i)))
|
|
return FALSE;
|
|
|
|
*val = (1 << i) - 1 + value;
|
|
|
|
return TRUE;
|
|
}
|
|
|
|
gboolean
|
|
nal_reader_get_se (NalReader * nr, gint32 * val)
|
|
{
|
|
guint32 value;
|
|
|
|
if (G_UNLIKELY (!nal_reader_get_ue (nr, &value)))
|
|
return FALSE;
|
|
|
|
if (value % 2)
|
|
*val = (value / 2) + 1;
|
|
else
|
|
*val = -(value / 2);
|
|
|
|
return TRUE;
|
|
}
|
|
|
|
gboolean
|
|
nal_reader_is_byte_aligned (NalReader * nr)
|
|
{
|
|
if (nr->bits_in_cache != 0)
|
|
return FALSE;
|
|
return TRUE;
|
|
}
|
|
|
|
gboolean
|
|
nal_reader_has_more_data (NalReader * nr)
|
|
{
|
|
NalReader nr_tmp;
|
|
guint remaining, nbits;
|
|
guint8 rbsp_stop_one_bit, zero_bits;
|
|
|
|
remaining = nal_reader_get_remaining (nr);
|
|
if (remaining == 0)
|
|
return FALSE;
|
|
|
|
nr_tmp = *nr;
|
|
nr = &nr_tmp;
|
|
|
|
/* The spec defines that more_rbsp_data() searches for the last bit
|
|
equal to 1, and that it is the rbsp_stop_one_bit. Subsequent bits
|
|
until byte boundary is reached shall be zero.
|
|
|
|
This means that more_rbsp_data() is FALSE if the next bit is 1
|
|
and the remaining bits until byte boundary are zero. One way to
|
|
be sure that this bit was the very last one, is that every other
|
|
bit after we reached byte boundary are also set to zero.
|
|
Otherwise, if the next bit is 0 or if there are non-zero bits
|
|
afterwards, then then we have more_rbsp_data() */
|
|
if (!nal_reader_get_bits_uint8 (nr, &rbsp_stop_one_bit, 1))
|
|
return FALSE;
|
|
if (!rbsp_stop_one_bit)
|
|
return TRUE;
|
|
|
|
nbits = --remaining % 8;
|
|
while (remaining > 0) {
|
|
if (!nal_reader_get_bits_uint8 (nr, &zero_bits, nbits))
|
|
return FALSE;
|
|
if (zero_bits != 0)
|
|
return TRUE;
|
|
remaining -= nbits;
|
|
nbits = 8;
|
|
}
|
|
return FALSE;
|
|
}
|
|
|
|
/*********** end of nal parser ***************/
|
|
|
|
gint
|
|
scan_for_start_codes (const guint8 * data, guint size)
|
|
{
|
|
GstByteReader br;
|
|
gst_byte_reader_init (&br, data, size);
|
|
|
|
/* NALU not empty, so we can at least expect 1 (even 2) bytes following sc */
|
|
return gst_byte_reader_masked_scan_uint32 (&br, 0xffffff00, 0x00000100,
|
|
0, size);
|
|
}
|
|
|
|
void
|
|
nal_writer_init (NalWriter * nw, guint nal_prefix_size, gboolean packetized)
|
|
{
|
|
g_return_if_fail (nw != NULL);
|
|
g_return_if_fail ((packetized && nal_prefix_size > 1 && nal_prefix_size < 5)
|
|
|| (!packetized && (nal_prefix_size == 3 || nal_prefix_size == 4)));
|
|
|
|
gst_bit_writer_init (&nw->bw);
|
|
nw->nal_prefix_size = nal_prefix_size;
|
|
nw->packetized = packetized;
|
|
}
|
|
|
|
void
|
|
nal_writer_reset (NalWriter * nw)
|
|
{
|
|
g_return_if_fail (nw != NULL);
|
|
|
|
gst_bit_writer_reset (&nw->bw);
|
|
memset (nw, 0, sizeof (NalWriter));
|
|
}
|
|
|
|
gboolean
|
|
nal_writer_do_rbsp_trailing_bits (NalWriter * nw)
|
|
{
|
|
g_return_val_if_fail (nw != NULL, FALSE);
|
|
|
|
if (!gst_bit_writer_put_bits_uint8 (&nw->bw, 1, 1)) {
|
|
GST_WARNING ("Cannot put trailing bits");
|
|
return FALSE;
|
|
}
|
|
|
|
if (!gst_bit_writer_align_bytes (&nw->bw, 0)) {
|
|
GST_WARNING ("Cannot put align bits");
|
|
return FALSE;
|
|
}
|
|
|
|
return TRUE;
|
|
}
|
|
|
|
static gpointer
|
|
nal_writer_create_nal_data (NalWriter * nw, guint32 * ret_size)
|
|
{
|
|
GstBitWriter bw;
|
|
gint i;
|
|
guint8 *src, *dst;
|
|
gsize size;
|
|
gpointer data;
|
|
|
|
/* scan to put emulation_prevention_three_byte */
|
|
size = GST_BIT_WRITER_BIT_SIZE (&nw->bw) >> 3;
|
|
src = GST_BIT_WRITER_DATA (&nw->bw);
|
|
|
|
gst_bit_writer_init_with_size (&bw, size + nw->nal_prefix_size, FALSE);
|
|
for (i = 0; i < nw->nal_prefix_size - 1; i++)
|
|
gst_bit_writer_put_bits_uint8 (&bw, 0, 8);
|
|
gst_bit_writer_put_bits_uint8 (&bw, 1, 8);
|
|
|
|
for (i = 0; i < size; i++) {
|
|
guint pos = (GST_BIT_WRITER_BIT_SIZE (&bw) >> 3);
|
|
dst = GST_BIT_WRITER_DATA (&bw);
|
|
if (pos >= nw->nal_prefix_size + 2 &&
|
|
dst[pos - 2] == 0 && dst[pos - 1] == 0 && src[i] <= 0x3) {
|
|
gst_bit_writer_put_bits_uint8 (&bw, 0x3, 8);
|
|
}
|
|
|
|
gst_bit_writer_put_bits_uint8 (&bw, src[i], 8);
|
|
}
|
|
|
|
*ret_size = bw.bit_size >> 3;
|
|
data = gst_bit_writer_reset_and_get_data (&bw);
|
|
|
|
if (nw->packetized) {
|
|
size = *ret_size - nw->nal_prefix_size;
|
|
|
|
switch (nw->nal_prefix_size) {
|
|
case 1:
|
|
GST_WRITE_UINT8 (data, size);
|
|
break;
|
|
case 2:
|
|
GST_WRITE_UINT16_BE (data, size);
|
|
break;
|
|
case 3:
|
|
GST_WRITE_UINT24_BE (data, size);
|
|
break;
|
|
case 4:
|
|
GST_WRITE_UINT32_BE (data, size);
|
|
break;
|
|
default:
|
|
g_assert_not_reached ();
|
|
break;
|
|
}
|
|
}
|
|
|
|
return data;
|
|
}
|
|
|
|
GstMemory *
|
|
nal_writer_reset_and_get_memory (NalWriter * nw)
|
|
{
|
|
guint32 size = 0;
|
|
GstMemory *ret = NULL;
|
|
gpointer data;
|
|
|
|
g_return_val_if_fail (nw != NULL, NULL);
|
|
|
|
if ((GST_BIT_WRITER_BIT_SIZE (&nw->bw) >> 3) == 0) {
|
|
GST_WARNING ("No written byte");
|
|
goto done;
|
|
}
|
|
|
|
if ((GST_BIT_WRITER_BIT_SIZE (&nw->bw) & 0x7) != 0) {
|
|
GST_WARNING ("Written stream is not byte aligned");
|
|
if (!nal_writer_do_rbsp_trailing_bits (nw))
|
|
goto done;
|
|
}
|
|
|
|
data = nal_writer_create_nal_data (nw, &size);
|
|
if (!data) {
|
|
GST_WARNING ("Failed to create nal data");
|
|
goto done;
|
|
}
|
|
|
|
ret = gst_memory_new_wrapped (0, data, size, 0, size, data, g_free);
|
|
|
|
done:
|
|
gst_bit_writer_reset (&nw->bw);
|
|
|
|
return ret;
|
|
}
|
|
|
|
guint8 *
|
|
nal_writer_reset_and_get_data (NalWriter * nw, guint32 * ret_size)
|
|
{
|
|
guint32 size = 0;
|
|
guint8 *data = NULL;
|
|
|
|
g_return_val_if_fail (nw != NULL, NULL);
|
|
g_return_val_if_fail (ret_size != NULL, NULL);
|
|
|
|
*ret_size = 0;
|
|
|
|
if ((GST_BIT_WRITER_BIT_SIZE (&nw->bw) >> 3) == 0) {
|
|
GST_WARNING ("No written byte");
|
|
goto done;
|
|
}
|
|
|
|
if ((GST_BIT_WRITER_BIT_SIZE (&nw->bw) & 0x7) != 0) {
|
|
GST_WARNING ("Written stream is not byte aligned");
|
|
if (!nal_writer_do_rbsp_trailing_bits (nw))
|
|
goto done;
|
|
}
|
|
|
|
data = nal_writer_create_nal_data (nw, &size);
|
|
if (!data) {
|
|
GST_WARNING ("Failed to create nal data");
|
|
goto done;
|
|
}
|
|
|
|
*ret_size = size;
|
|
|
|
done:
|
|
gst_bit_writer_reset (&nw->bw);
|
|
|
|
return data;
|
|
}
|
|
|
|
gboolean
|
|
nal_writer_put_bits_uint8 (NalWriter * nw, guint8 value, guint nbits)
|
|
{
|
|
g_return_val_if_fail (nw != NULL, FALSE);
|
|
|
|
if (!gst_bit_writer_put_bits_uint8 (&nw->bw, value, nbits))
|
|
return FALSE;
|
|
|
|
return TRUE;
|
|
}
|
|
|
|
gboolean
|
|
nal_writer_put_bits_uint16 (NalWriter * nw, guint16 value, guint nbits)
|
|
{
|
|
g_return_val_if_fail (nw != NULL, FALSE);
|
|
|
|
if (!gst_bit_writer_put_bits_uint16 (&nw->bw, value, nbits))
|
|
return FALSE;
|
|
|
|
return TRUE;
|
|
}
|
|
|
|
gboolean
|
|
nal_writer_put_bits_uint32 (NalWriter * nw, guint32 value, guint nbits)
|
|
{
|
|
g_return_val_if_fail (nw != NULL, FALSE);
|
|
|
|
if (!gst_bit_writer_put_bits_uint32 (&nw->bw, value, nbits))
|
|
return FALSE;
|
|
|
|
return TRUE;
|
|
}
|
|
|
|
gboolean
|
|
nal_writer_put_bytes (NalWriter * nw, const guint8 * data, guint nbytes)
|
|
{
|
|
g_return_val_if_fail (nw != NULL, FALSE);
|
|
g_return_val_if_fail (data != NULL, FALSE);
|
|
g_return_val_if_fail (nbytes != 0, FALSE);
|
|
|
|
if (!gst_bit_writer_put_bytes (&nw->bw, data, nbytes))
|
|
return FALSE;
|
|
|
|
return TRUE;
|
|
}
|
|
|
|
gboolean
|
|
nal_writer_put_ue (NalWriter * nw, guint32 value)
|
|
{
|
|
guint leading_zeros;
|
|
guint rest;
|
|
|
|
g_return_val_if_fail (nw != NULL, FALSE);
|
|
|
|
count_exp_golomb_bits (value, &leading_zeros, &rest);
|
|
|
|
/* write leading zeros */
|
|
if (leading_zeros) {
|
|
if (!nal_writer_put_bits_uint32 (nw, 0, leading_zeros))
|
|
return FALSE;
|
|
}
|
|
|
|
/* write the rest */
|
|
if (!nal_writer_put_bits_uint32 (nw, value + 1, rest))
|
|
return FALSE;
|
|
|
|
return TRUE;
|
|
}
|
|
|
|
gboolean
|
|
count_exp_golomb_bits (guint32 value, guint * leading_zeros, guint * rest)
|
|
{
|
|
guint32 x;
|
|
guint count = 0;
|
|
|
|
/* https://en.wikipedia.org/wiki/Exponential-Golomb_coding */
|
|
/* count bits of value + 1 */
|
|
x = value + 1;
|
|
while (x) {
|
|
count++;
|
|
x >>= 1;
|
|
}
|
|
|
|
if (leading_zeros) {
|
|
if (count > 1)
|
|
*leading_zeros = count - 1;
|
|
else
|
|
*leading_zeros = 0;
|
|
}
|
|
|
|
if (rest) {
|
|
*rest = count;
|
|
}
|
|
|
|
return TRUE;
|
|
}
|