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libobs: Add HEVC parsing functions 

Also create obs_nal_find_startcode from obs_avc_find_startcode to share
with HEVC functions.
master
jpark37 2022-02-24 21:26:54 -08:00 committed by Jim
parent 484881fe2e
commit 76893fb7b9
6 changed files with 294 additions and 53 deletions
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4
libobs/CMakeLists.txt
View File

@ -31,11 +31,15 @@ target_sources(
obs-encoder.c
obs-encoder.h
obs-ffmpeg-compat.h
obs-hevc.c
obs-hevc.h
obs-hotkey.c
obs-hotkey.h
obs-hotkeys.h
obs-missing-files.c
obs-missing-files.h
obs-nal.c
obs-nal.h
obs-hotkey-name-map.c
obs-interaction.h
obs-internal.h

62
libobs/obs-avc.c
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@ -15,17 +15,18 @@
along with this program. If not, see <http://www.gnu.org/licenses/>.
******************************************************************************/
#include "obs.h"
#include "obs-avc.h"
#include "obs.h"
#include "obs-nal.h"
#include "util/array-serializer.h"
bool obs_avc_keyframe(const uint8_t *data, size_t size)
{
const uint8_t *nal_start, *nal_end;
const uint8_t *end = data + size;
int type;
nal_start = obs_avc_find_startcode(data, end);
nal_start = obs_nal_find_startcode(data, end);
while (true) {
while (nal_start < end && !*(nal_start++))
;
@ -33,65 +34,21 @@ bool obs_avc_keyframe(const uint8_t *data, size_t size)
if (nal_start == end)
break;
type = nal_start[0] & 0x1F;
const uint8_t type = nal_start[0] & 0x1F;
if (type == OBS_NAL_SLICE_IDR || type == OBS_NAL_SLICE)
return (type == OBS_NAL_SLICE_IDR);
return type == OBS_NAL_SLICE_IDR;
nal_end = obs_avc_find_startcode(nal_start, end);
nal_end = obs_nal_find_startcode(nal_start, end);
nal_start = nal_end;
}
return false;
}
/* NOTE: I noticed that FFmpeg does some unusual special handling of certain
* scenarios that I was unaware of, so instead of just searching for {0, 0, 1}
* we'll just use the code from FFmpeg - http://www.ffmpeg.org/ */
static const uint8_t *ff_avc_find_startcode_internal(const uint8_t *p,
const uint8_t *end)
{
const uint8_t *a = p + 4 - ((intptr_t)p & 3);
for (end -= 3; p < a && p < end; p++) {
if (p[0] == 0 && p[1] == 0 && p[2] == 1)
return p;
}
for (end -= 3; p < end; p += 4) {
uint32_t x = *(const uint32_t *)p;
if ((x - 0x01010101) & (~x) & 0x80808080) {
if (p[1] == 0) {
if (p[0] == 0 && p[2] == 1)
return p;
if (p[2] == 0 && p[3] == 1)
return p + 1;
}
if (p[3] == 0) {
if (p[2] == 0 && p[4] == 1)
return p + 2;
if (p[4] == 0 && p[5] == 1)
return p + 3;
}
}
}
for (end += 3; p < end; p++) {
if (p[0] == 0 && p[1] == 0 && p[2] == 1)
return p;
}
return end + 3;
}
const uint8_t *obs_avc_find_startcode(const uint8_t *p, const uint8_t *end)
{
const uint8_t *out = ff_avc_find_startcode_internal(p, end);
if (p < out && out < end && !out[-1])
out--;
return out;
return obs_nal_find_startcode(p, end);
}
static inline int get_drop_priority(int priority)
@ -233,7 +190,6 @@ void obs_extract_avc_headers(const uint8_t *packet, size_t size,
DARRAY(uint8_t) sei;
const uint8_t *nal_start, *nal_end, *nal_codestart;
const uint8_t *end = packet + size;
int type;
da_init(new_packet);
da_init(header);
@ -250,7 +206,7 @@ void obs_extract_avc_headers(const uint8_t *packet, size_t size,
if (nal_start == end)
break;
type = nal_start[0] & 0x1F;
const uint8_t type = nal_start[0] & 0x1F;
nal_end = obs_avc_find_startcode(nal_start, end);
if (!nal_end)

148
libobs/obs-hevc.c Normal file
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@ -0,0 +1,148 @@
/******************************************************************************
Copyright (C) 2022 by Hugh Bailey <obs.jim@gmail.com>
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 2 of the License, or
(at your option) any later version.
This program 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
******************************************************************************/
#include "obs-hevc.h"
#include "obs-nal.h"
#include "util/darray.h"
enum {
OBS_HEVC_NAL_TRAIL_N = 0,
OBS_HEVC_NAL_TRAIL_R = 1,
OBS_HEVC_NAL_TSA_N = 2,
OBS_HEVC_NAL_TSA_R = 3,
OBS_HEVC_NAL_STSA_N = 4,
OBS_HEVC_NAL_STSA_R = 5,
OBS_HEVC_NAL_RADL_N = 6,
OBS_HEVC_NAL_RADL_R = 7,
OBS_HEVC_NAL_RASL_N = 8,
OBS_HEVC_NAL_RASL_R = 9,
OBS_HEVC_NAL_VCL_N10 = 10,
OBS_HEVC_NAL_VCL_R11 = 11,
OBS_HEVC_NAL_VCL_N12 = 12,
OBS_HEVC_NAL_VCL_R13 = 13,
OBS_HEVC_NAL_VCL_N14 = 14,
OBS_HEVC_NAL_VCL_R15 = 15,
OBS_HEVC_NAL_BLA_W_LP = 16,
OBS_HEVC_NAL_BLA_W_RADL = 17,
OBS_HEVC_NAL_BLA_N_LP = 18,
OBS_HEVC_NAL_IDR_W_RADL = 19,
OBS_HEVC_NAL_IDR_N_LP = 20,
OBS_HEVC_NAL_CRA_NUT = 21,
OBS_HEVC_NAL_RSV_IRAP_VCL22 = 22,
OBS_HEVC_NAL_RSV_IRAP_VCL23 = 23,
OBS_HEVC_NAL_RSV_VCL24 = 24,
OBS_HEVC_NAL_RSV_VCL25 = 25,
OBS_HEVC_NAL_RSV_VCL26 = 26,
OBS_HEVC_NAL_RSV_VCL27 = 27,
OBS_HEVC_NAL_RSV_VCL28 = 28,
OBS_HEVC_NAL_RSV_VCL29 = 29,
OBS_HEVC_NAL_RSV_VCL30 = 30,
OBS_HEVC_NAL_RSV_VCL31 = 31,
OBS_HEVC_NAL_VPS = 32,
OBS_HEVC_NAL_SPS = 33,
OBS_HEVC_NAL_PPS = 34,
OBS_HEVC_NAL_AUD = 35,
OBS_HEVC_NAL_EOS_NUT = 36,
OBS_HEVC_NAL_EOB_NUT = 37,
OBS_HEVC_NAL_FD_NUT = 38,
OBS_HEVC_NAL_SEI_PREFIX = 39,
OBS_HEVC_NAL_SEI_SUFFIX = 40,
};
bool obs_hevc_keyframe(const uint8_t *data, size_t size)
{
const uint8_t *nal_start, *nal_end;
const uint8_t *end = data + size;
nal_start = obs_nal_find_startcode(data, end);
while (true) {
while (nal_start < end && !*(nal_start++))
;
if (nal_start == end)
break;
const uint8_t type = (nal_start[0] & 0x7F) >> 1;
if (type <= OBS_HEVC_NAL_RSV_IRAP_VCL23)
return type >= OBS_HEVC_NAL_BLA_W_LP;
nal_end = obs_nal_find_startcode(nal_start, end);
nal_start = nal_end;
}
return false;
}
void obs_extract_hevc_headers(const uint8_t *packet, size_t size,
uint8_t **new_packet_data,
size_t *new_packet_size, uint8_t **header_data,
size_t *header_size, uint8_t **sei_data,
size_t *sei_size)
{
DARRAY(uint8_t) new_packet;
DARRAY(uint8_t) header;
DARRAY(uint8_t) sei;
const uint8_t *nal_start, *nal_end, *nal_codestart;
const uint8_t *end = packet + size;
da_init(new_packet);
da_init(header);
da_init(sei);
nal_start = obs_nal_find_startcode(packet, end);
nal_end = NULL;
while (nal_end != end) {
nal_codestart = nal_start;
while (nal_start < end && !*(nal_start++))
;
if (nal_start == end)
break;
const uint8_t type = (nal_start[0] & 0x7F) >> 1;
nal_end = obs_nal_find_startcode(nal_start, end);
if (!nal_end)
nal_end = end;
if (type == OBS_HEVC_NAL_VPS || type == OBS_HEVC_NAL_SPS ||
type == OBS_HEVC_NAL_PPS) {
da_push_back_array(header, nal_codestart,
nal_end - nal_codestart);
} else if (type == OBS_HEVC_NAL_SEI_PREFIX ||
type == OBS_HEVC_NAL_SEI_SUFFIX) {
da_push_back_array(sei, nal_codestart,
nal_end - nal_codestart);
} else {
da_push_back_array(new_packet, nal_codestart,
nal_end - nal_codestart);
}
nal_start = nal_end;
}
*new_packet_data = new_packet.array;
*new_packet_size = new_packet.num;
*header_data = header.array;
*header_size = header.num;
*sei_data = sei.array;
*sei_size = sei.num;
}

35
libobs/obs-hevc.h Normal file
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@ -0,0 +1,35 @@
/******************************************************************************
Copyright (C) 2022 by Hugh Bailey <obs.jim@gmail.com>
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 2 of the License, or
(at your option) any later version.
This program 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
******************************************************************************/
#pragma once
#include "util/c99defs.h"
#ifdef __cplusplus
extern "C" {
#endif
EXPORT bool obs_hevc_keyframe(const uint8_t *data, size_t size);
EXPORT void obs_extract_hevc_headers(const uint8_t *packet, size_t size,
uint8_t **new_packet_data,
size_t *new_packet_size,
uint8_t **header_data, size_t *header_size,
uint8_t **sei_data, size_t *sei_size);
#ifdef __cplusplus
}
#endif

67
libobs/obs-nal.c Normal file
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@ -0,0 +1,67 @@
/******************************************************************************
Copyright (C) 2022 by Hugh Bailey <obs.jim@gmail.com>
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 2 of the License, or
(at your option) any later version.
This program 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
******************************************************************************/
#include "obs-nal.h"
/* NOTE: I noticed that FFmpeg does some unusual special handling of certain
* scenarios that I was unaware of, so instead of just searching for {0, 0, 1}
* we'll just use the code from FFmpeg - http://www.ffmpeg.org/ */
static const uint8_t *ff_avc_find_startcode_internal(const uint8_t *p,
const uint8_t *end)
{
const uint8_t *a = p + 4 - ((intptr_t)p & 3);
for (end -= 3; p < a && p < end; p++) {
if (p[0] == 0 && p[1] == 0 && p[2] == 1)
return p;
}
for (end -= 3; p < end; p += 4) {
uint32_t x = *(const uint32_t *)p;
if ((x - 0x01010101) & (~x) & 0x80808080) {
if (p[1] == 0) {
if (p[0] == 0 && p[2] == 1)
return p;
if (p[2] == 0 && p[3] == 1)
return p + 1;
}
if (p[3] == 0) {
if (p[2] == 0 && p[4] == 1)
return p + 2;
if (p[4] == 0 && p[5] == 1)
return p + 3;
}
}
}
for (end += 3; p < end; p++) {
if (p[0] == 0 && p[1] == 0 && p[2] == 1)
return p;
}
return end + 3;
}
const uint8_t *obs_nal_find_startcode(const uint8_t *p, const uint8_t *end)
{
const uint8_t *out = ff_avc_find_startcode_internal(p, end);
if (p < out && out < end && !out[-1])
out--;
return out;
}

31
libobs/obs-nal.h Normal file
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@ -0,0 +1,31 @@
/******************************************************************************
Copyright (C) 2022 by Hugh Bailey <obs.jim@gmail.com>
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 2 of the License, or
(at your option) any later version.
This program 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
******************************************************************************/
#pragma once
#include "util/c99defs.h"
#ifdef __cplusplus
extern "C" {
#endif
EXPORT const uint8_t *obs_nal_find_startcode(const uint8_t *p,
const uint8_t *end);
#ifdef __cplusplus
}
#endif