strh header

Author: JonnyBurger

packages/media-parser/src/boxes/riff/parse-avih.ts

@@ -9,6 +9,7 @@ export const parseAvih = ({
 	size: number;
 }): RiffBox => {
 	const {expectNoMoreBytes} = iterator.startBox(size);
+
 	const dwMicroSecPerFrame = iterator.getUint32Le();
 	const dwMaxBytesPerSec = iterator.getUint32Le();
 	const paddingGranularity = iterator.getUint32Le();

packages/media-parser/src/boxes/riff/parse-riff-box.ts

@@ -2,6 +2,7 @@ import type {BufferIterator} from '../../buffer-iterator';
 import {parseAvih} from './parse-avih';
 import {parseFmtBox} from './parse-fmt-box';
 import {parseListBox} from './parse-list-box';
+import {parseStrh} from './parse-strh';
 import type {RiffBox, RiffRegularBox} from './riff-box';
 
 export const parseRiffBox = ({
@@ -27,6 +28,10 @@ export const parseRiffBox = ({
 		return parseAvih({iterator, size});
 	}
 
+	if (id === 'strh') {
+		return parseStrh({iterator, size});
+	}
+
 	iterator.discard(size);
 
 	const box: RiffRegularBox = {

packages/media-parser/src/boxes/riff/parse-strh.ts

@@ -0,0 +1,61 @@
+import type {BufferIterator} from '../../buffer-iterator';
+import type {RiffBox} from './riff-box';
+
+export const parseStrh = ({
+	iterator,
+	size,
+}: {
+	iterator: BufferIterator;
+	size: number;
+}): RiffBox => {
+	const box = iterator.startBox(size);
+	const fccType = iterator.getByteString(4);
+	if (fccType !== 'vids' && fccType !== 'auds') {
+		throw new Error('Expected AVI handler to be vids / auds');
+	}
+
+	const handler =
+		fccType === 'vids' ? iterator.getByteString(4) : iterator.getUint32Le();
+	if (typeof handler === 'string' && handler !== 'H264') {
+		throw new Error(
+			`Only H264 is supported as a stream type in .avi, got ${handler}`,
+		);
+	}
+
+	if (fccType === 'auds' && handler !== 1) {
+		throw new Error(
+			`Only "1" is supported as a stream type in .avi, got ${handler}`,
+		);
+	}
+
+	const flags = iterator.getUint32Le();
+	const priority = iterator.getUint16Le();
+	const language = iterator.getUint16Le();
+	const initialFrames = iterator.getUint32Le();
+	const scale = iterator.getUint32Le();
+	const rate = iterator.getUint32Le();
+	const start = iterator.getUint32Le();
+	const length = iterator.getUint32Le();
+	const suggestedBufferSize = iterator.getUint32Le();
+	const quality = iterator.getUint32Le();
+	const sampleSize = iterator.getUint32Le();
+
+	box.discardRest();
+
+	return {
+		type: 'strh-box',
+		fccType,
+		handler,
+		flags,
+		priority,
+		initialFrames,
+		length,
+		quality,
+		rate,
+		sampleSize,
+		scale,
+		start,
+		suggestedBufferSize,
+		language,
+	};
+};

packages/media-parser/src/boxes/riff/riff-box.ts

@@ -34,6 +34,23 @@ export type AvihBox = {
 	height: number;
 };
 
+export type StrhBox = {
+	type: 'strh-box';
+	fccType: 'vids' | 'auds';
+	handler: 'H264' | number;
+	flags: number;
+	priority: number;
+	initialFrames: number;
+	scale: number;
+	rate: number;
+	start: number;
+	length: number;
+	suggestedBufferSize: number;
+	quality: number;
+	sampleSize: number;
+	language: number;
+};
+
 export type RiffHeader = {
 	type: 'riff-header';
 	fileSize: number;
@@ -45,4 +62,5 @@ export type RiffBox =
 	| WaveFormatBox
 	| RiffHeader
 	| ListBox
-	| AvihBox;
+	| AvihBox
+	| StrhBox;

packages/media-parser/src/test/parse-avi-file.test.ts

@@ -35,9 +35,20 @@ test('AVI file', async () => {
 				{
 					children: [
 						{
-							id: 'strh',
-							size: 56,
-							type: 'riff-box',
+							type: 'strh-box',
+							fccType: 'vids',
+							handler: 'H264',
+							flags: 0,
+							initialFrames: 0,
+							scale: 1,
+							length: 901,
+							priority: 0,
+							quality: 4294967295,
+							rate: 30,
+							sampleSize: 0,
+							start: 0,
+							suggestedBufferSize: 4796,
+							language: 0,
 						},
 						{
 							id: 'strf',
@@ -61,9 +72,20 @@ test('AVI file', async () => {
 				{
 					children: [
 						{
-							id: 'strh',
-							size: 56,
-							type: 'riff-box',
+							type: 'strh-box',
+							fccType: 'auds',
+							handler: 1,
+							flags: 0,
+							priority: 0,
+							initialFrames: 0,
+							scale: 8,
+							rate: 375,
+							length: 1435,
+							quality: 4294967295,
+							sampleSize: 0,
+							start: 0,
+							suggestedBufferSize: 373,
+							language: 0,
 						},
 						{
 							id: 'strf',