I'm trying to execute a rather trivial WebAssembly benchmark with Google's V8 engine (both in-browser using the current Version of Google Chrome (Version 83.0.4103.106, 64-bit) and via embedding V8 (Version 8.5.183) in a C++ program. All benchmarks are executed on macOS 10.14.6 with an Intel i7 8850H processor. No RAM swap has been used.
I am using the following C code as a benchmark. (Note that runtime is in the order of seconds on a current Intel Core i7)
static void init(int n, int path[1000][1000]) {
for (int i = 0; i < n; i++) {
for (int j = 0; j < n; j++) {
path[i][j] = i*j%7+1;
if ((i+j)%13 == 0 || (i+j)%7==0 || (i+j)%11 == 0) {
path[i][j] = 999;
}
}
}
}
static void kernel(int n, int path[1000][1000]) {
for (int k = 0; k < n; k++) {
for(int i = 0; i < n; i++) {
for (int j = 0; j < n; j++) {
path[i][j] = path[i][j] < path[i][k] + path[k][j] ? path[i][j] : path[i][k] + path[k][j];
}
}
}
}
int path[1000][1000];
int main(void) {
int n = 1000;
init(n, path);
kernel(n, path);
return 0;
}
This can be easily executed via https://wasdk.github.io/WasmFiddle/. The corresponding JS code measuring time in the most basic way is the following:
var wasmModule = new WebAssembly.Module(wasmCode);
var wasmInstance = new WebAssembly.Instance(wasmModule, wasmImports);
var a = new Date();
wasmInstance.exports.main();
var b = new Date();
log(b-a);
The result I'm getting in browser (e.g. in WasmFiddle or on a custom website) in Google Chrome is the following (for multiple consecutive executions) in milliseconds:
3687
1757
1837
1753
1726
1731
1774
1741
1771
1727
3549
1742
1731
1847
1734
1745
3515
1731
1772
Note the outliers performing at half the speed of the rest. How and why are there outliers with still such consistent performance? As much care as possible has been taken to ensure that no other processes are using up CPU time.
For the embedded version, the monolithic V8 library has been built from source using the following build config:
is_component_build = false
is_debug = false
target_cpu = "x64"
use_custom_libcxx = false
v8_monolithic = true
v8_use_external_startup_data = false
v8_enable_pointer_compression = false
The C++ code embedding the V8 library and executing the Wasm script (The Wasm code is the exact code produced by the WasmFiddle compiler):
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "include/libplatform/libplatform.h"
#include "include/v8.h"
int main(int argc, char* argv[]) {
// Initialize V8.
v8::V8::InitializeICUDefaultLocation(argv[0]);
v8::V8::InitializeExternalStartupData(argv[0]);
std::unique_ptr<v8::Platform> platform = v8::platform::NewDefaultPlatform();
v8::V8::InitializePlatform(platform.get());
v8::V8::Initialize();
// Create a new Isolate and make it the current one.
v8::Isolate::CreateParams create_params;
create_params.array_buffer_allocator = v8::ArrayBuffer::Allocator::NewDefaultAllocator();
v8::Isolate* isolate = v8::Isolate::New(create_params);
{
v8::Isolate::Scope isolate_scope(isolate);
// Create a stack-allocated handle scope.
v8::HandleScope handle_scope(isolate);
// Create a new context.
v8::Local<v8::Context> context = v8::Context::New(isolate);
v8::Context::Scope context_scope(context);
{
const char csource[] = R"(
let bytes = new Uint8Array([
0x0, 0x61, 0x73, 0x6D, 0x01, 0x00, 0x00, 0x00, 0x01, 0x85, 0x80, 0x80, 0x80, 0x00, 0x01, 0x60,
0x00, 0x01, 0x7F, 0x03, 0x82, 0x80, 0x80, 0x80, 0x00, 0x01, 0x00, 0x04, 0x84, 0x80, 0x80, 0x80,
0x00, 0x01, 0x70, 0x00, 0x00, 0x05, 0x83, 0x80, 0x80, 0x80, 0x00, 0x01, 0x00, 0x3E, 0x06, 0x81,
0x80, 0x80, 0x80, 0x00, 0x00, 0x07, 0x91, 0x80, 0x80, 0x80, 0x00, 0x02, 0x06, 0x6D, 0x65, 0x6D,
0x6F, 0x72, 0x79, 0x02, 0x00, 0x04, 0x6D, 0x61, 0x69, 0x6E, 0x00, 0x00, 0x0A, 0x8F, 0x82, 0x80,
0x80, 0x00, 0x01, 0x89, 0x82, 0x80, 0x80, 0x00, 0x01, 0x08, 0x7F, 0x41, 0x00, 0x21, 0x02, 0x41,
0x10, 0x21, 0x05, 0x03, 0x40, 0x20, 0x05, 0x21, 0x07, 0x41, 0x00, 0x21, 0x04, 0x41, 0x00, 0x21,
0x03, 0x03, 0x40, 0x20, 0x07, 0x20, 0x04, 0x41, 0x07, 0x6F, 0x41, 0x01, 0x6A, 0x41, 0xE7, 0x07,
0x20, 0x02, 0x20, 0x03, 0x6A, 0x22, 0x00, 0x41, 0x07, 0x6F, 0x1B, 0x41, 0xE7, 0x07, 0x20, 0x00,
0x41, 0x0D, 0x6F, 0x1B, 0x41, 0xE7, 0x07, 0x20, 0x00, 0x41, 0x0B, 0x6F, 0x1B, 0x36, 0x02, 0x00,
0x20, 0x07, 0x41, 0x04, 0x6A, 0x21, 0x07, 0x20, 0x04, 0x20, 0x02, 0x6A, 0x21, 0x04, 0x20, 0x03,
0x41, 0x01, 0x6A, 0x22, 0x03, 0x41, 0xE8, 0x07, 0x47, 0x0D, 0x00, 0x0B, 0x20, 0x05, 0x41, 0xA0,
0x1F, 0x6A, 0x21, 0x05, 0x20, 0x02, 0x41, 0x01, 0x6A, 0x22, 0x02, 0x41, 0xE8, 0x07, 0x47, 0x0D,
0x00, 0x0B, 0x41, 0x00, 0x21, 0x06, 0x41, 0x10, 0x21, 0x05, 0x03, 0x40, 0x41, 0x10, 0x21, 0x00,
0x41, 0x00, 0x21, 0x01, 0x03, 0x40, 0x20, 0x01, 0x41, 0xA0, 0x1F, 0x6C, 0x20, 0x06, 0x41, 0x02,
0x74, 0x6A, 0x41, 0x10, 0x6A, 0x21, 0x02, 0x41, 0x00, 0x21, 0x07, 0x03, 0x40, 0x20, 0x00, 0x20,
0x07, 0x6A, 0x22, 0x04, 0x20, 0x04, 0x28, 0x02, 0x00, 0x22, 0x04, 0x20, 0x05, 0x20, 0x07, 0x6A,
0x28, 0x02, 0x00, 0x20, 0x02, 0x28, 0x02, 0x00, 0x6A, 0x22, 0x03, 0x20, 0x04, 0x20, 0x03, 0x48,
0x1B, 0x36, 0x02, 0x00, 0x20, 0x07, 0x41, 0x04, 0x6A, 0x22, 0x07, 0x41, 0xA0, 0x1F, 0x47, 0x0D,
0x00, 0x0B, 0x20, 0x00, 0x41, 0xA0, 0x1F, 0x6A, 0x21, 0x00, 0x20, 0x01, 0x41, 0x01, 0x6A, 0x22,
0x01, 0x41, 0xE8, 0x07, 0x47, 0x0D, 0x00, 0x0B, 0x20, 0x05, 0x41, 0xA0, 0x1F, 0x6A, 0x21, 0x05,
0x20, 0x06, 0x41, 0x01, 0x6A, 0x22, 0x06, 0x41, 0xE8, 0x07, 0x47, 0x0D, 0x00, 0x0B, 0x41, 0x00,
0x0B
]);
let module = new WebAssembly.Module(bytes);
let instance = new WebAssembly.Instance(module);
instance.exports.main();
)";
// Create a string containing the JavaScript source code.
v8::Local<v8::String> source = v8::String::NewFromUtf8Literal(isolate, csource);
// Compile the source code.
v8::Local<v8::Script> script = v8::Script::Compile(context, source).ToLocalChecked();
// Run the script to get the result.
v8::Local<v8::Value> result = script->Run(context).ToLocalChecked();
}
}
// Dispose the isolate and tear down V8.
isolate->Dispose();
v8::V8::Dispose();
v8::V8::ShutdownPlatform();
delete create_params.array_buffer_allocator;
return 0;
}
I compile it as follows:
g++ -I. -O2 -Iinclude samples/wasm.cc -o wasm -lv8_monolith -Lout.gn/x64.release.sample/obj/ -pthread -std=c++17
On execution with time ./wasm, I get execution times between 4.9s and 5.1s - almost triple that of in-Chrome/WasmFiddle execution! Did I miss anything? Maybe some optimization switches? This result is perfectly reproducible and I have even tested various different versions of the V8 library - still the same result.
Ah, the joys of microbenchmarking :-)
V8 has two compilers for Wasm: a non-optimizing baseline compiler that produces code really fast, and an optimizing compiler that takes quite a bit longer to produce code, but that code is typically about twice as fast. When a module is loaded, current versions first compile all functions with the baseline compiler. Once that's done, execution can start, and optimized compilation jobs are scheduled to run in the background. When an optimized compilation job is complete, the respective function's code is swapped, and the next invocation of the function will use it. (The details here will very likely change in the future, but the general principle will remain.) That way, typical applications get both good startup latency, and good peak performance.
But, as with any heuristic or strategy, you can craft a case where it gets it wrong...
In your benchmark, each function is called only once. In the fast cases, optimizing kernel finishes before init returns. In the slow cases, kernel is called before its optimized compilation job is done, so its baseline version runs. Apparently when embedding V8 directly, you reliably get the latter scenario, whereas when running via WasmFiddle in Chrome, you get the former most of the time, but not always.
I can't explain why your custom embedding runs are even slower than the slow case in Chrome; I'm not seeing that on my machine (OTOH, in Chrome, I'm seeing an even bigger delta: about 1100ms for a fast run and 4400ms for a slow run); however I used the d8 shell instead of compiling my own embedding. One thing that's different is that when measuring with time on the command line, you include process startup and initialization, which the Date.now() calls around main() don't include. But that should only account for 10-50 milliseconds or so, not for a 3.6s → 5.0s difference.
While this situation might look quite unfortunate for your microbenchmark, it is generally working as intended, i.e. not a bug, and hence unlikely to change on V8's side. There are several things you can do to make the benchmark more reflective of real-world behavior (assuming this one doesn't exactly represent some real application you have):
execute functions multiple times; you'll see that the first run will be slower (or, depending on function size and module size and number of available CPU cores and scheduling luck, the first few runs)
wait a bit before calling the hottest functions, e.g. by doing
var wasmModule = new WebAssembly.Module(wasmCode);
var wasmInstance = new WebAssembly.Instance(wasmModule, wasmImports);
window.setTimeout(() => {
var a = Date.now();
wasmInstance.exports.main();
var b = Date.now();
log(b-a);
}, 10);
In my tests with d8 I've found that even a silly busy-wait did the trick:
let wait = Date.now() + 10;
while (Date.now() < wait) {}
instance.exports.main();
generally make the benchmark bigger and more complex: have and execute more different functions, don't just spend 99% of the time in a single line.
(FWIW, the earliest V8 versions that supported WebAssembly had no tiering, only optimized compilation. So modules always had to wait for that to finish. It was not a good user experience; for large modules the wait time could be tens of seconds. Having a baseline compiler is quite clearly the better solution overall, even if it comes at the cost of not having maximum performance available immediately. Looking good on artificial one-liners is not what matters in practice; providing a good user experience for large real-world applications matters.)
I'm trying to rotate a h264 video 90 degrees anticlockwise. The syntax for the Display Orientation Supplementary EnhancementInformation (SEI) is given as:
Which I first tried encoding as follows:
val prefix = byteArrayOf(0, 0, 0, 1)
val nalHeader = byteArrayOf(6) // 0 forbidden_zero_bit = 0, nal_ref_idc = 0, nal_unit_type = 6
val display = byteArrayOf(47 /* Display orientation type*/, 3 /*payload size*/)
val displayOrientationCancelFlag = "0" // u(1); Rotation information follows
val horFlip = "0" // hor_flip; u(1); Do not flip horizontally
val verFlip = "0" // ver_flip; u(1); Do not flip vertically
val anticlockwiseRotation = "0100000000000000" // u(16); value / 2^16 -> 90 degrees
val displayOrientationRepetitionPeriod = "010" // ue(v); Persistent till next video sequence
val displayOrientationExtensionFlag = "0" // u(1); No other value is permitted by the spec atm
val byteAlignment = "1"
The above is my kotlin code for generating the SEI. This is a static variable so I went for human readable version.
Dropping the Annex B start codes, the hex SEI is
06 2f 03 08 00 09
ffmpeg complained about this however, saying that my payload size was specified as 3 bytes (24 bits) but it only read 23 bits before reading the NAL stop bit. To fix this I padded my SEI payload by one zero bit to allow ffmpeg parse it successfully, and added the stop bit again with more byte alignment bits:
val byteAlignment = "010000000"
This in hex is
06 2f 03 08 00 08 80
When I add this before the first IDR NAL unit in my h264 rbsp, ffmpeg will accept it to convert to whatever format I ask, jpeg or mp4. The output is not rotated however. Playing it with ffplay also does not rotate it. I'm note quite sure what I'm doing wrong. ffprobe yields the following output:
[NULL # 0x7fca03808a00] Opening 'sei2.264' for reading
[file # 0x7fca01c289c0] Setting default whitelist 'file,crypto'
Probing h264 score:51 size:1502
Probing mp3 score:1 size:1502
[h264 # 0x7fca03808a00] Format h264 probed with size=2048 and score=51
[h264 # 0x7fca03808a00] Before avformat_find_stream_info() pos: 0 bytes read:1502 seeks:0 nb_streams:1
[AVBSFContext # 0x7fca02808680] nal_unit_type: 7(SPS), nal_ref_idc: 3
[AVBSFContext # 0x7fca02808680] nal_unit_type: 8(PPS), nal_ref_idc: 3
[AVBSFContext # 0x7fca02808680] nal_unit_type: 6(SEI), nal_ref_idc: 0
[AVBSFContext # 0x7fca02808680] nal_unit_type: 5(IDR), nal_ref_idc: 3
[h264 # 0x7fca0381d400] nal_unit_type: 7(SPS), nal_ref_idc: 3
[h264 # 0x7fca0381d400] nal_unit_type: 8(PPS), nal_ref_idc: 3
[h264 # 0x7fca0381d400] nal_unit_type: 6(SEI), nal_ref_idc: 0
[h264 # 0x7fca0381d400] nal_unit_type: 5(IDR), nal_ref_idc: 3
[h264 # 0x7fca0381d400] Format yuv420p chosen by get_format().
[h264 # 0x7fca0381d400] Reinit context to 176x144, pix_fmt: yuv420p
[h264 # 0x7fca03808a00] decoding for stream 0 failed
[h264 # 0x7fca03808a00] stream 0: start_time: -7686143364045.646 duration: -7686143364045.646
[h264 # 0x7fca03808a00] format: start_time: -9223372036854.775 duration: -9223372036854.775 bitrate=0 kb/s
[h264 # 0x7fca03808a00] After avformat_find_stream_info() pos: 1502 bytes read:1502 seeks:0 frames:1
Input #0, h264, from 'sei2.264':
Duration: N/A, bitrate: N/A
Stream #0:0, 1, 1/1200000: Video: h264 (Constrained Baseline), 1 reference frame, yuv420p(progressive, left), 176x144, 0/1, 25 tbr, 1200k tbn, 50 tbc
[h264 # 0x7fca0380dc00] nal_unit_type: 7(SPS), nal_ref_idc: 3
[h264 # 0x7fca0380dc00] nal_unit_type: 8(PPS), nal_ref_idc: 3
[AVIOContext # 0x7fca02801b00] Statistics: 1502 bytes read, 0 seeks
My full RBSP with SPS, PPS, SEI and IDR follow:
unsigned char rbsp[1502] = {
// Offset 0x00000000 to 0x00001501
0x00, 0x00, 0x00, 0x01, 0x67, 0x42, 0xc0, 0x29, 0x8d, 0x68, 0x2c, 0x4e,
0x80, 0x78, 0x44, 0x23, 0x50, 0x00, 0x00, 0x00, 0x01, 0x68, 0xce, 0x01,
0xa8, 0x35, 0xc8, 0x00, 0x00, 0x00, 0x01, 0x06, 0x2f, 0x03, 0x08, 0x00,
0x08, 0x80, 0x00, 0x00, 0x00, 0x01, 0x65, 0xb8, 0x00, 0x04, 0x05, 0x9f,
0xff, 0xff, 0x04, 0x51, 0x40, 0x00, 0x41, 0x63, 0xc7, 0x31, 0xcf, 0xff,
0xff, 0x27, 0xff, 0xfe, 0x4f, 0xff, 0xfc, 0x9f, 0xff, 0xf9, 0x3f, 0xff,
0xf2, 0x7f, 0xff, 0xe4, 0xff, 0xff, 0xc9, 0xff, 0xff, 0x93, 0xff, 0xff,
0x27, 0xff, 0xfe, 0x4f, 0xff, 0xfc, 0x9f, 0xff, 0xf9, 0x3f, 0xff, 0xf2,
0x7f, 0xff, 0xe4, 0xff, 0xfc, 0x43, 0x05, 0xd0, 0x03, 0x2b, 0x2d, 0x11,
0x03, 0x16, 0x84, 0xb4, 0x5e, 0xc2, 0x00, 0x03, 0xa0, 0x20, 0xc7, 0x42,
0xb6, 0xb8, 0x00, 0x57, 0x66, 0x66, 0x09, 0xdc, 0xc1, 0x92, 0x50, 0x86,
0x38, 0x04, 0x8f, 0x6d, 0x83, 0xff, 0xff, 0x41, 0x5e, 0xef, 0xbb, 0xff,
0xff, 0xd0, 0x57, 0xbb, 0xee, 0xff, 0xff, 0xf4, 0x15, 0xee, 0xfb, 0xbf,
0xff, 0xfd, 0x05, 0x7b, 0xbe, 0xef, 0xff, 0xff, 0x41, 0x5e, 0xef, 0xbb,
0xff, 0xff, 0xd0, 0x57, 0xbb, 0xc0, 0x25, 0x55, 0x9a, 0xdf, 0x9f, 0x22,
0x63, 0xff, 0xff, 0x27, 0xff, 0xfe, 0x4f, 0xff, 0xfc, 0x9f, 0xff, 0xf9,
0x3f, 0xff, 0xec, 0x86, 0xfc, 0x7d, 0x2d, 0x2f, 0xf8, 0x07, 0xfa, 0xf8,
0x00, 0x37, 0x66, 0x35, 0x11, 0x29, 0x61, 0x8b, 0x30, 0x53, 0x41, 0x3c,
0xb3, 0xee, 0x59, 0xa7, 0xb7, 0xc2, 0x00, 0x03, 0x00, 0x07, 0x05, 0x86,
0x02, 0x10, 0x88, 0x38, 0x00, 0x53, 0x68, 0x93, 0x1b, 0xf4, 0x22, 0x3b,
0x90, 0x00, 0x08, 0x30, 0xd9, 0x64, 0x00, 0x02, 0x0c, 0x36, 0xe6, 0x10,
0xef, 0xa0, 0xf6, 0x52, 0xc3, 0xd9, 0x5c, 0xf8, 0x1f, 0xff, 0xb0, 0xdf,
0x80, 0x06, 0xc6, 0xaa, 0x46, 0x19, 0xd8, 0x55, 0x96, 0x5f, 0xfb, 0x38,
0xc2, 0xf8, 0x40, 0x00, 0x64, 0x0a, 0x0a, 0x30, 0x11, 0x20, 0xd4, 0x00,
0x8c, 0x99, 0xb0, 0x6c, 0xd9, 0x4a, 0x10, 0xde, 0x0c, 0x80, 0x00, 0x83,
0x8c, 0xb9, 0x88, 0xed, 0x77, 0x3c, 0x85, 0x1d, 0xcd, 0x2f, 0xff, 0xc7,
0x9c, 0x3b, 0xc0, 0xe8, 0x22, 0xb2, 0xbe, 0x04, 0xdf, 0xdf, 0xfe, 0x42,
0x80, 0x0b, 0x83, 0x88, 0xa5, 0x81, 0xc0, 0x02, 0x05, 0x08, 0x96, 0x00,
0x43, 0x64, 0x44, 0x09, 0xdf, 0xa1, 0x03, 0x88, 0xbe, 0x0d, 0x9c, 0xb1,
0x23, 0x3a, 0xe7, 0xff, 0xfd, 0x93, 0xff, 0xff, 0x27, 0xe2, 0x1f, 0xf8,
0x2c, 0x80, 0xf2, 0x10, 0xf2, 0xdf, 0x08, 0x00, 0x44, 0x00, 0x18, 0x0e,
0x81, 0x20, 0x02, 0x24, 0x0e, 0x00, 0x10, 0x20, 0x44, 0xbf, 0x06, 0xa7,
0x2f, 0xfc, 0xbf, 0x0c, 0x01, 0x02, 0xf8, 0xc4, 0xcf, 0x07, 0xc0, 0xe0,
0x00, 0x80, 0x08, 0x0f, 0x65, 0x84, 0x04, 0x0a, 0x8a, 0x03, 0x83, 0x44,
0xc0, 0x02, 0x92, 0x22, 0x20, 0x6c, 0xd9, 0x08, 0x1c, 0xfe, 0x03, 0x80,
0x8c, 0x5c, 0xb2, 0x00, 0x46, 0x2e, 0x5e, 0x04, 0x6c, 0xbb, 0x80, 0x71,
0x08, 0xf2, 0xc8, 0x10, 0x8f, 0x2c, 0x5a, 0xf2, 0x74, 0x0d, 0xb7, 0xf8,
0xd3, 0xed, 0x6d, 0x7f, 0xfc, 0x38, 0x03, 0x0e, 0xf8, 0x00, 0xee, 0x12,
0x89, 0xef, 0x22, 0x09, 0x97, 0xd3, 0xdf, 0x30, 0xc1, 0x48, 0x01, 0x80,
0x06, 0x9b, 0x80, 0x05, 0x64, 0xcd, 0x98, 0x9b, 0x29, 0x48, 0x74, 0x22,
0x32, 0x4b, 0xe0, 0x0f, 0x06, 0xd8, 0x61, 0x77, 0xb8, 0x70, 0x11, 0x8b,
0x97, 0xff, 0xc1, 0x30, 0x06, 0x1d, 0xf0, 0x00, 0xdc, 0xa1, 0x16, 0x88,
0xd5, 0xcc, 0x49, 0x17, 0xd9, 0xe8, 0x36, 0x61, 0x05, 0x55, 0x80, 0xe0,
0x0c, 0x37, 0x00, 0x21, 0xb4, 0x4a, 0x1b, 0xf4, 0x25, 0x8a, 0x40, 0x08,
0xc5, 0xcb, 0xe0, 0x70, 0x64, 0xa2, 0x13, 0xbd, 0xc3, 0x88, 0x47, 0x97,
0xf9, 0xf8, 0x07, 0xb0, 0x5f, 0x8e, 0xcc, 0xe0, 0xf8, 0x00, 0xac, 0x2f,
0x8e, 0xe6, 0x11, 0x2f, 0x51, 0xea, 0xf0, 0x40, 0xbb, 0x30, 0x4b, 0x4b,
0x0e, 0x02, 0x31, 0x72, 0xfc, 0x38, 0x84, 0x79, 0x7f, 0xe1, 0xff, 0xb0,
0x59, 0xea, 0xcf, 0xdc, 0x66, 0x12, 0xc3, 0xd5, 0xf2, 0xbd, 0x3c, 0x76,
0x02, 0x47, 0xae, 0x3d, 0xff, 0xf0, 0x24, 0x5c, 0xb3, 0xd2, 0x26, 0x2b,
0x9f, 0xf1, 0xfe, 0xc1, 0x6c, 0xf4, 0x1e, 0xe1, 0x00, 0x00, 0x80, 0x30,
0x03, 0x07, 0x97, 0x08, 0x4c, 0x85, 0x81, 0xc0, 0x02, 0x04, 0x08, 0x97,
0xe0, 0xd4, 0xe5, 0xff, 0xff, 0xf6, 0x16, 0xdb, 0xee, 0xfd, 0x1f, 0x6b,
0x6b, 0x6b, 0x6b, 0x6b, 0xc3, 0xff, 0xf6, 0x08, 0xbe, 0x0b, 0x44, 0xaf,
0xf9, 0xff, 0xb0, 0x59, 0xe0, 0x0d, 0x5f, 0x6a, 0x38, 0xde, 0x82, 0x01,
0x20, 0xc4, 0x80, 0x78, 0x00, 0x56, 0x46, 0x66, 0x84, 0xd9, 0x4a, 0xac,
0xd2, 0x00, 0x02, 0x05, 0x08, 0xb9, 0x04, 0xdf, 0xf6, 0x95, 0x9d, 0xce,
0x01, 0x82, 0xfc, 0x34, 0x3b, 0xee, 0x47, 0xc0, 0x4f, 0xaf, 0xad, 0x6f,
0x5e, 0x10, 0x17, 0x1d, 0x82, 0xc6, 0x35, 0xa0, 0x01, 0x4d, 0x91, 0x13,
0x1b, 0xf4, 0x26, 0x57, 0xc8, 0x00, 0x04, 0x08, 0x13, 0x71, 0xc6, 0x81,
0x23, 0x5b, 0xd6, 0x51, 0x2b, 0x9f, 0xff, 0xf6, 0x1f, 0xef, 0x3b, 0xcf,
0x53, 0xd7, 0x5d, 0x75, 0xd7, 0x4f, 0xff, 0xff, 0xc1, 0x07, 0x01, 0xc0,
0x21, 0xce, 0x2e, 0x5b, 0xff, 0xff, 0xb0, 0x43, 0xe0, 0x03, 0x6d, 0x10,
0xe1, 0x0a, 0x27, 0xa4, 0xdd, 0xa1, 0xce, 0x03, 0xda, 0x72, 0xdf, 0xfe,
0x29, 0x6a, 0xa5, 0xea, 0xa5, 0x80, 0x06, 0x0b, 0x68, 0x8a, 0x66, 0x62,
0xdf, 0xfc, 0x7e, 0xc1, 0x07, 0x01, 0xe6, 0x3a, 0x88, 0x7f, 0xd0, 0xe8,
0x00, 0xfc, 0x02, 0x67, 0xb1, 0xe0, 0x73, 0xd2, 0x2e, 0x03, 0xf8, 0x00,
0xc4, 0x00, 0x6f, 0x9b, 0x15, 0x6b, 0x2d, 0xcf, 0x07, 0xc0, 0x02, 0x09,
0x6a, 0x32, 0xd8, 0xba, 0x3f, 0x0c, 0x28, 0x20, 0x28, 0x20, 0x20, 0x42,
0x00, 0x83, 0xe0, 0x70, 0x23, 0x15, 0x2c, 0x01, 0x03, 0x2a, 0x63, 0xcc,
0x42, 0x99, 0x02, 0x19, 0xee, 0x01, 0xc8, 0x46, 0x96, 0x00, 0x47, 0x6c,
0xd8, 0x04, 0xaa, 0x41, 0xbc, 0x41, 0x05, 0x32, 0x00, 0x08, 0x20, 0xab,
0x9f, 0xff, 0xf4, 0x0a, 0xb4, 0xab, 0x8d, 0x3e, 0x09, 0x25, 0xff, 0xff,
0xe8, 0x9f, 0xff, 0xf4, 0x4f, 0xff, 0xfa, 0x27, 0xff, 0xfd, 0x07, 0x30,
0x04, 0x2d, 0x20, 0x47, 0x38, 0x95, 0xab, 0xfc, 0x00, 0x6b, 0x19, 0x05,
0xce, 0x53, 0x10, 0xa6, 0xed, 0x08, 0x12, 0xc0, 0x90, 0x00, 0x26, 0x1a,
0x00, 0x21, 0xfb, 0x90, 0xfc, 0x84, 0x24, 0x10, 0xcd, 0x72, 0x00, 0x14,
0xd2, 0x35, 0x91, 0x86, 0x37, 0x5e, 0x9b, 0x20, 0x00, 0x41, 0x05, 0xdc,
0xff, 0xe0, 0x18, 0x57, 0xe0, 0x02, 0x98, 0xf7, 0x33, 0x98, 0x55, 0x3d,
0x47, 0xab, 0xdf, 0xe8, 0x30, 0x01, 0xab, 0x58, 0x48, 0x53, 0xb1, 0x8a,
0x7a, 0xbd, 0xd5, 0x8f, 0x87, 0xe0, 0x01, 0x0c, 0xa4, 0x12, 0xad, 0xcc,
0x29, 0x1a, 0xd0, 0x83, 0xd9, 0xc2, 0x9a, 0xf4, 0xd0, 0x38, 0x08, 0xa4,
0xcb, 0xf2, 0xfc, 0xb0, 0xe0, 0x9c, 0x79, 0x7f, 0xff, 0xfe, 0x10, 0x61,
0xef, 0xc0, 0x01, 0x93, 0x46, 0x83, 0x76, 0xea, 0x41, 0x8d, 0xf7, 0x4b,
0x14, 0x1c, 0x00, 0x04, 0x10, 0x20, 0x18, 0x00, 0x08, 0x14, 0xf0, 0x91,
0xcd, 0xb8, 0x08, 0xd4, 0xb7, 0xcf, 0x7f, 0xff, 0xd0, 0x43, 0xdf, 0xd0,
0x81, 0x83, 0xca, 0xc0, 0x05, 0x34, 0x63, 0x27, 0x15, 0x4d, 0x52, 0x0d,
0xda, 0x5e, 0x30, 0x5e, 0x05, 0x2a, 0x0d, 0xbb, 0x90, 0x22, 0x03, 0x7a,
0x68, 0x1d, 0x21, 0xdc, 0xd4, 0xc8, 0x91, 0x4d, 0xf3, 0xcf, 0xff, 0xfa,
0x05, 0x9c, 0x53, 0xfa, 0x45, 0xff, 0xe3, 0x4f, 0xff, 0xfe, 0x82, 0xdb,
0x7d, 0xdf, 0x1c, 0x00, 0x0d, 0xc7, 0x00, 0x01, 0x01, 0x5f, 0xff, 0xfd,
0x06, 0xae, 0xf9, 0x7d, 0x31, 0xf1, 0x08, 0xe2, 0x00, 0x00, 0x80, 0x30,
0x03, 0xea, 0x2e, 0x30, 0x92, 0x6b, 0xc8, 0x70, 0x98, 0x6b, 0x90, 0xe1,
0x30, 0xd7, 0x3f, 0xf0, 0xc0, 0x34, 0x0b, 0x60, 0x00, 0x99, 0x90, 0xc8,
0xe1, 0x98, 0xdc, 0x41, 0x23, 0xcc, 0x71, 0xf0, 0x40, 0xc6, 0x17, 0xc2,
0x80, 0x07, 0xc0, 0x81, 0x40, 0x00, 0xf8, 0x09, 0xc0, 0x27, 0xb1, 0x37,
0x72, 0x02, 0xa7, 0xd5, 0xe2, 0xc0, 0x80, 0xa6, 0x78, 0x04, 0xe9, 0x89,
0x95, 0xc8, 0x0e, 0xbf, 0x57, 0x8b, 0x00, 0x80, 0x53, 0x3f, 0xf5, 0xf0,
0xd8, 0x76, 0x00, 0x09, 0xe4, 0x38, 0xcc, 0x7e, 0x90, 0x66, 0x90, 0xb5,
0x86, 0x08, 0x50, 0x00, 0x6c, 0x99, 0xb4, 0x44, 0x8c, 0x6a, 0x89, 0xc4,
0xf8, 0x27, 0xf8, 0x41, 0x1f, 0xdc, 0x10, 0x47, 0xf7, 0x60, 0x04, 0x9d,
0x0f, 0x31, 0x5c, 0x9e, 0xaf, 0x0e, 0x09, 0x89, 0x81, 0x0d, 0x34, 0xdb,
0x56, 0x00, 0x48, 0xd4, 0x34, 0x62, 0xb9, 0xbd, 0x5e, 0x1c, 0x05, 0xd9,
0x81, 0x0d, 0x34, 0xdb, 0x57, 0xfc, 0x03, 0x0e, 0x81, 0x54, 0x20, 0x04,
0x86, 0x28, 0x40, 0x09, 0x0c, 0x5f, 0xc0, 0x15, 0x24, 0x63, 0x05, 0x38,
0xc3, 0x6d, 0x5f, 0x58, 0x02, 0xa1, 0x67, 0x70, 0x53, 0x0c, 0x36, 0xd5,
0xff, 0xf0, 0x0d, 0x87, 0x70, 0x00, 0x4c, 0xc8, 0x64, 0x70, 0xcc, 0x6e,
0x20, 0x91, 0xe6, 0x38, 0xfc, 0x61, 0x70, 0x40, 0xfc, 0x20, 0x08, 0x75,
0x94, 0x10, 0x04, 0x15, 0x66, 0x61, 0x35, 0xc3, 0xec, 0x47, 0x2f, 0xab,
0xc5, 0x81, 0x01, 0x4c, 0xe1, 0x32, 0x70, 0xd5, 0x88, 0xe7, 0xf5, 0x78,
0xb0, 0x08, 0x05, 0x33, 0xff, 0x05, 0xfd, 0x82, 0xff, 0xaf, 0x80, 0x02,
0x79, 0x0e, 0x33, 0x1f, 0xa4, 0x19, 0xa4, 0x2d, 0x70, 0x42, 0x08, 0x01,
0x3c, 0x06, 0x08, 0x01, 0x38, 0x25, 0x43, 0x82, 0x61, 0x6e, 0x00, 0x12,
0xf0, 0x9b, 0x39, 0x41, 0x51, 0xea, 0xf1, 0x00, 0x98, 0x5b, 0x90, 0xe4,
0x64, 0xb8, 0x00, 0x4a, 0xd0, 0x99, 0x1c, 0xa0, 0x55, 0x7a, 0xbc, 0x41,
0x19, 0x2e, 0x7f, 0xff, 0xd0, 0x63, 0x2e, 0xa6, 0x3c, 0x00, 0x19, 0xb4,
0x49, 0x8d, 0xfa, 0x11, 0x1d, 0xd2, 0x33, 0xe8, 0xef, 0xff, 0xfe, 0xfc,
0x07, 0x00, 0x10, 0x41, 0xaa, 0x4b, 0x7e, 0x00, 0x0d, 0xd3, 0x26, 0xc4,
0xf3, 0x15, 0x1d, 0x13, 0x9f, 0x04, 0x2c, 0x0e, 0x00, 0xc1, 0x02, 0x40,
0x07, 0x81, 0xb4, 0x70, 0x75, 0x43, 0xf0, 0x3c, 0xc5, 0x70, 0x8f, 0xff,
0xff, 0xb0, 0xc7, 0x80, 0x03, 0x36, 0x89, 0x31, 0xbf, 0xc4, 0x47, 0x7d,
0x04, 0xfb, 0xf8, 0x07, 0xff, 0xb0, 0x45, 0xcb, 0x9e, 0xc2, 0x05, 0xd9,
0x82, 0x00, 0x11, 0x58, 0xaf, 0xff, 0xfb, 0x08, 0xdf, 0xff, 0xff, 0x61,
0x1b, 0x7f, 0xff, 0xec, 0x15, 0x76, 0xff, 0xff, 0xdd, 0xff, 0xff, 0xec,
0x15, 0x44, 0x7b, 0xff, 0xcd, 0x7f, 0xff, 0xec, 0x23, 0x77, 0xff, 0xfe,
0xc8, 0x9f
}
The payloadSize is only the the size of the sei_message() The stop bit is not included in this size. So there must be a 0x80 at the end of the SEI,