Expectation

web/apps/photos/src/constants/ffmpeg.ts

@@ -1,3 +1,3 @@
-export const INPUT_PATH_PLACEHOLDER = "INPUT";
-export const FFMPEG_PLACEHOLDER = "FFMPEG";
-export const OUTPUT_PATH_PLACEHOLDER = "OUTPUT";
+export const ffmpegPathPlaceholder = "FFMPEG";
+export const inputPathPlaceholder = "INPUT";
+export const outputPathPlaceholder = "OUTPUT";

web/apps/photos/src/services/ffmpeg.ts

@@ -2,9 +2,9 @@ import { ComlinkWorker } from "@/next/worker/comlink-worker";
 import { validateAndGetCreationUnixTimeInMicroSeconds } from "@ente/shared/time";
 import { Remote } from "comlink";
 import {
-    FFMPEG_PLACEHOLDER,
-    INPUT_PATH_PLACEHOLDER,
-    OUTPUT_PATH_PLACEHOLDER,
+    ffmpegPathPlaceholder,
+    inputPathPlaceholder,
+    outputPathPlaceholder,
 } from "constants/ffmpeg";
 import { NULL_LOCATION } from "constants/upload";
 import { ElectronFile, ParsedExtractedMetadata } from "types/upload";
@@ -19,16 +19,16 @@ export async function generateVideoThumbnail(
         try {
             return await ffmpegExec(
                 [
-                    FFMPEG_PLACEHOLDER,
+                    ffmpegPathPlaceholder,
                     "-i",
-                    INPUT_PATH_PLACEHOLDER,
+                    inputPathPlaceholder,
                     "-ss",
                     `00:00:0${seekTime}`,
                     "-vframes",
                     "1",
                     "-vf",
                     "scale=-1:720",
-                    OUTPUT_PATH_PLACEHOLDER,
+                    outputPathPlaceholder,
                 ],
                 file,
                 "thumb.jpeg",
@@ -50,16 +50,16 @@ export async function extractVideoMetadata(file: File | ElectronFile) {
     // -f ffmetadata [https://ffmpeg.org/ffmpeg-formats.html#Metadata-1] => dump metadata from media files into a simple UTF-8-encoded INI-like text file
     const metadata = await ffmpegExec(
         [
-            FFMPEG_PLACEHOLDER,
+            ffmpegPathPlaceholder,
             "-i",
-            INPUT_PATH_PLACEHOLDER,
+            inputPathPlaceholder,
             "-c",
             "copy",
             "-map_metadata",
             "0",
             "-f",
             "ffmetadata",
-            OUTPUT_PATH_PLACEHOLDER,
+            outputPathPlaceholder,
         ],
         file,
         `metadata.txt`,
@@ -137,16 +137,16 @@ function parseCreationTime(creationTime: string) {
 export async function convertToMP4(file: File) {
     return await ffmpegExec(
         [
-            FFMPEG_PLACEHOLDER,
+            ffmpegPathPlaceholder,
             "-i",
-            INPUT_PATH_PLACEHOLDER,
+            inputPathPlaceholder,
             "-preset",
             "ultrafast",
-            OUTPUT_PATH_PLACEHOLDER,
+            outputPathPlaceholder,
         ],
         file,
         "output.mp4",
-        true,
+        30 * 1000,
     );
 }
 
@@ -164,21 +164,16 @@ const ffmpegExec = async (
     cmd: string[],
     inputFile: File | ElectronFile,
     outputFilename: string,
-    dontTimeout?: boolean,
+    timeoutMS: number = 0,
 ): Promise<File | ElectronFile> => {
     const electron = globalThis.electron;
     if (electron) {
-        return electron.runFFmpegCmd(
-            cmd,
-            inputFile,
-            outputFilename,
-            dontTimeout,
-        );
+        return electron.runFFmpegCmd(cmd, inputFile, outputFilename, timeoutMS);
     } else {
         return workerFactory
             .instance()
             .then((worker) =>
-                worker.run(cmd, inputFile, outputFilename, dontTimeout),
+                worker.run(cmd, inputFile, outputFilename, timeoutMS),
             );
     }
 };

web/apps/photos/src/worker/ffmpeg.worker.ts

@@ -3,29 +3,34 @@ import log from "@/next/log";
 import { withTimeout } from "@ente/shared/utils";
 import QueueProcessor from "@ente/shared/utils/queueProcessor";
 import { generateTempName } from "@ente/shared/utils/temp";
-import * as Comlink from "comlink";
+import { expose } from "comlink";
 import {
-    FFMPEG_PLACEHOLDER,
-    INPUT_PATH_PLACEHOLDER,
-    OUTPUT_PATH_PLACEHOLDER,
+    ffmpegPathPlaceholder,
+    inputPathPlaceholder,
+    outputPathPlaceholder,
 } from "constants/ffmpeg";
 import { FFmpeg, createFFmpeg } from "ffmpeg-wasm";
 import { getUint8ArrayView } from "services/readerService";
 
 export class DedicatedFFmpegWorker {
-    wasmFFmpeg: WasmFFmpeg;
+    private wasmFFmpeg: WasmFFmpeg;
+
     constructor() {
         this.wasmFFmpeg = new WasmFFmpeg();
     }
 
-    run(cmd, inputFile, outputFileName, dontTimeout) {
-        return this.wasmFFmpeg.run(cmd, inputFile, outputFileName, dontTimeout);
+    /**
+     * Execute a FFMPEG {@link command}.
+     *
+     * This is a sibling of {@link ffmpegExec} in ipc.ts exposed by the desktop
+     * app. See [Note: FFMPEG in Electron].
+     */
+    run(cmd, inputFile, outputFileName, timeoutMS) {
+        return this.wasmFFmpeg.run(cmd, inputFile, outputFileName, timeoutMS);
     }
 }
 
-Comlink.expose(DedicatedFFmpegWorker, self);
-
-const FFMPEG_EXECUTION_WAIT_TIME = 30 * 1000;
+expose(DedicatedFFmpegWorker, self);
 
 export class WasmFFmpeg {
     private ffmpeg: FFmpeg;
@@ -51,24 +56,13 @@ export class WasmFFmpeg {
         cmd: string[],
         inputFile: File,
         outputFileName: string,
-        dontTimeout = false,
+        timeoutMS,
     ) {
-        const response = this.ffmpegTaskQueue.queueUpRequest(() => {
-            if (dontTimeout) {
-                return this.execute(cmd, inputFile, outputFileName);
-            } else {
-                return withTimeout<File>(
-                    this.execute(cmd, inputFile, outputFileName),
-                    FFMPEG_EXECUTION_WAIT_TIME,
-                );
-            }
-        });
-        try {
-            return await response.promise;
-        } catch (e) {
-            log.error("ffmpeg run failed", e);
-            throw e;
-        }
+        const exec = () => this.execute(cmd, inputFile, outputFileName);
+        const request = this.ffmpegTaskQueue.queueUpRequest(() =>
+            timeoutMS ? withTimeout<File>(exec(), timeoutMS) : exec(),
+        );
+        return await request.promise;
     }
 
     private async execute(
@@ -91,11 +85,11 @@ export class WasmFFmpeg {
             tempOutputFilePath = `${generateTempName(10, outputFileName)}`;
 
             cmd = cmd.map((cmdPart) => {
-                if (cmdPart === FFMPEG_PLACEHOLDER) {
+                if (cmdPart === ffmpegPathPlaceholder) {
                     return "";
-                } else if (cmdPart === INPUT_PATH_PLACEHOLDER) {
+                } else if (cmdPart === inputPathPlaceholder) {
                     return tempInputFilePath;
-                } else if (cmdPart === OUTPUT_PATH_PLACEHOLDER) {
+                } else if (cmdPart === outputPathPlaceholder) {
                     return tempOutputFilePath;
                 } else {
                     return cmdPart;

web/packages/next/types/ipc.ts

@@ -236,11 +236,40 @@ export interface Electron {
         maxSize: number,
     ) => Promise<Uint8Array>;
 
-    runFFmpegCmd: (
-        cmd: string[],
-        inputFile: File | ElectronFile,
+    /**
+     * Execute a FFMPEG {@link command}.
+     *
+     * This executes the command using the FFMPEG executable we bundle with our
+     * desktop app. There is also a FFMPEG WASM implementation that we use when
+     * running on the web, it also has a sibling function with the same
+     * parameters. See [Note: FFMPEG in Electron].
+     *
+     * @param command An array of strings, each representing one positional
+     * parameter in the command to execute. Placeholders for the input, output
+     * and ffmpeg's own path are replaced before executing the command
+     * (respectively {@link inputPathPlaceholder},
+     * {@link outputPathPlaceholder}, {@link ffmpegPathPlaceholder}).
+     *
+     * @param inputDataOrPath The bytes of the input file, or the path to the
+     * input file on the user's local disk. In both cases, the data gets
+     * serialized to a temporary file, and then that path gets substituted in
+     * the FFMPEG {@link command} by {@link inputPathPlaceholder}.
+     *
+     * @param outputFileName The name of the file we instruct FFMPEG to produce
+     * when giving it the given {@link command}. The contents of this file get
+     * returned as the result.
+     *
+     * @param timeoutMS If non-zero, then throw a timeout error if the FFMPEG
+     * command takes more than the given number of milliseconds.
+     *
+     * @returns The contents of the output file produced by the ffmpeg command
+     * at {@link outputFileName}.
+     */
+    ffmpegExec: (
+        command: string[],
+        inputDataOrPath: Uint8Array | string,
         outputFileName: string,
-        dontTimeout?: boolean,
+        timeoutMS: number,
     ) => Promise<File>;
 
     // - ML