Add video file metadata to download modal, via ffprobe (#2411)

* Add video file metadata via ffprobe

* Federate video file metadata

* Add tests for file metadata generation

* Complete tests for videoFile metadata federation

* Lint migration and video-file for metadata

* Objectify metadata from getter in ffmpeg-utils

* Add metadataUrl to all videoFiles

* Simplify metadata API middleware

* Load playlist in videoFile when requesting metadata

4 files changed, 186 insertions, 5 deletions

diff --git a/client/src/app/shared/video/modals/video-download.component.html b/client/src/app/shared/video/modals/video-download.component.html
index 976da03f3..391fe245e 100644
--- a/client/src/app/shared/video/modals/video-download.component.html
+++ b/client/src/app/shared/video/modals/video-download.component.html
@@ -20,7 +20,7 @@
     <div class="form-group">
       <div class="input-group input-group-sm">
         <div class="input-group-prepend peertube-select-container">
-          <select *ngIf="type === 'video'" [(ngModel)]="resolutionId">
+          <select *ngIf="type === 'video'" [(ngModel)]="resolutionId" (ngModelChange)="onResolutionIdChange()">
             <option *ngFor="let file of getVideoFiles()" [value]="file.resolution.id">{{ file.resolution.label }}</option>
           </select>
 
@@ -38,6 +38,42 @@
       </div>
     </div>
 
+    <ngb-tabset *ngIf="type === 'video' && videoFile?.metadata">
+      <ngb-tab>
+        <ng-template ngbTabTitle i18n>Format</ng-template>
+        <ng-template ngbTabContent>
+          <div class="file-metadata">
+            <div class="metadata-attribute metadata-attribute-tags" *ngFor="let item of videoFileMetadataFormat | keyvalue">
+              <span i18n class="metadata-attribute-label">{{ item.value.label }}</span>
+              <span class="metadata-attribute-value">{{ item.value.value }}</span>
+            </div>
+          </div>
+        </ng-template>
+      </ngb-tab>
+      <ngb-tab [disabled]="videoFileMetadataVideoStream === undefined">
+        <ng-template ngbTabTitle i18n>Video stream</ng-template>
+        <ng-template ngbTabContent>
+          <div class="file-metadata">
+            <div class="metadata-attribute metadata-attribute-tags" *ngFor="let item of videoFileMetadataVideoStream | keyvalue">
+              <span i18n class="metadata-attribute-label">{{ item.value.label }}</span>
+              <span class="metadata-attribute-value">{{ item.value.value }}</span>
+            </div>
+          </div>
+        </ng-template>
+      </ngb-tab>
+      <ngb-tab [disabled]="videoFileMetadataAudioStream === undefined">
+        <ng-template ngbTabTitle i18n>Audio stream</ng-template>
+        <ng-template ngbTabContent>
+          <div class="file-metadata">
+            <div class="metadata-attribute metadata-attribute-tags" *ngFor="let item of videoFileMetadataAudioStream | keyvalue">
+              <span i18n class="metadata-attribute-label">{{ item.value.label }}</span>
+              <span class="metadata-attribute-value">{{ item.value.value }}</span>
+            </div>
+          </div>
+        </ng-template>
+      </ngb-tab>
+    </ngb-tabset>
+
     <div class="download-type" *ngIf="type === 'video'">
       <div class="peertube-radio-container">
         <input type="radio" name="download" id="download-direct" [(ngModel)]="downloadType" value="direct">
diff --git a/client/src/app/shared/video/modals/video-download.component.scss b/client/src/app/shared/video/modals/video-download.component.scss
index 09dd91aa9..f28bc34ed 100644
--- a/client/src/app/shared/video/modals/video-download.component.scss
+++ b/client/src/app/shared/video/modals/video-download.component.scss
@@ -27,3 +27,38 @@
     margin-right: 30px;
   }
 }
+
+.file-metadata {
+  padding: 1rem;
+}
+
+.file-metadata .metadata-attribute {
+  font-size: 13px;
+  display: block;
+  margin-bottom: 12px;
+
+  .metadata-attribute-label {
+    min-width: 142px;
+    padding-right: 5px;
+    display: inline-block;
+    color: $grey-foreground-color;
+    font-weight: $font-bold;
+  }
+
+  a.metadata-attribute-value {
+    @include disable-default-a-behaviour;
+    color: var(--mainForegroundColor);
+
+    &:hover {
+      opacity: 0.9;
+    }
+  }
+
+  &.metadata-attribute-tags {
+    .metadata-attribute-value:not(:nth-child(2)) {
+      &::before {
+        content: ', '
+      }
+    }
+  }
+}
diff --git a/client/src/app/shared/video/modals/video-download.component.ts b/client/src/app/shared/video/modals/video-download.component.ts
index 6909c4279..d77187821 100644
--- a/client/src/app/shared/video/modals/video-download.component.ts
+++ b/client/src/app/shared/video/modals/video-download.component.ts
@@ -3,9 +3,15 @@ import { VideoDetails } from '../../../shared/video/video-details.model'
 import { NgbActiveModal, NgbModal } from '@ng-bootstrap/ng-bootstrap'
 import { I18n } from '@ngx-translate/i18n-polyfill'
 import { AuthService, Notifier } from '@app/core'
-import { VideoPrivacy, VideoCaption } from '@shared/models'
+import { VideoPrivacy, VideoCaption, VideoFile } from '@shared/models'
+import { FfprobeFormat, FfprobeStream } from 'fluent-ffmpeg'
+import { mapValues, pick } from 'lodash-es'
+import { NumberFormatterPipe } from '@app/shared/angular/number-formatter.pipe'
+import { BytesPipe } from 'ngx-pipes'
+import { VideoService } from '../video.service'
 
 type DownloadType = 'video' | 'subtitles'
+type FileMetadata = { [key: string]: { label: string, value: string }}
 
 @Component({
   selector: 'my-video-download',
@@ -20,17 +26,28 @@ export class VideoDownloadComponent {
   subtitleLanguageId: string
 
   video: VideoDetails
+  videoFile: VideoFile
+  videoFileMetadataFormat: FileMetadata
+  videoFileMetadataVideoStream: FileMetadata | undefined
+  videoFileMetadataAudioStream: FileMetadata | undefined
   videoCaptions: VideoCaption[]
   activeModal: NgbActiveModal
 
   type: DownloadType = 'video'
 
+  private bytesPipe: BytesPipe
+  private numbersPipe: NumberFormatterPipe
+
   constructor (
     private notifier: Notifier,
     private modalService: NgbModal,
+    private videoService: VideoService,
     private auth: AuthService,
     private i18n: I18n
-  ) { }
+  ) {
+    this.bytesPipe = new BytesPipe()
+    this.numbersPipe = new NumberFormatterPipe()
+  }
 
   get typeText () {
     return this.type === 'video'
@@ -51,6 +68,7 @@ export class VideoDownloadComponent {
     this.activeModal = this.modalService.open(this.modal, { centered: true })
 
     this.resolutionId = this.getVideoFiles()[0].resolution.id
+    this.onResolutionIdChange()
     if (this.videoCaptions) this.subtitleLanguageId = this.videoCaptions[0].language.id
   }
 
@@ -67,10 +85,27 @@ export class VideoDownloadComponent {
   getLink () {
     return this.type === 'subtitles' && this.videoCaptions
       ? this.getSubtitlesLink()
-      : this.getVideoLink()
+      : this.getVideoFileLink()
   }
 
-  getVideoLink () {
+  async onResolutionIdChange () {
+    this.videoFile = this.getVideoFile()
+    if (this.videoFile.metadata || !this.videoFile.metadataUrl) return
+
+    await this.hydrateMetadataFromMetadataUrl(this.videoFile)
+
+    this.videoFileMetadataFormat = this.videoFile
+      ? this.getMetadataFormat(this.videoFile.metadata.format)
+      : undefined
+    this.videoFileMetadataVideoStream = this.videoFile
+      ? this.getMetadataStream(this.videoFile.metadata.streams, 'video')
+      : undefined
+    this.videoFileMetadataAudioStream = this.videoFile
+      ? this.getMetadataStream(this.videoFile.metadata.streams, 'audio')
+      : undefined
+  }
+
+  getVideoFile () {
     // HTML select send us a string, so convert it to a number
     this.resolutionId = parseInt(this.resolutionId.toString(), 10)
 
@@ -79,6 +114,12 @@ export class VideoDownloadComponent {
       console.error('Could not find file with resolution %d.', this.resolutionId)
       return
     }
+    return file
+  }
+
+  getVideoFileLink () {
+    const file = this.videoFile
+    if (!file) return
 
     const suffix = this.video.privacy.id === VideoPrivacy.PRIVATE || this.video.privacy.id === VideoPrivacy.INTERNAL
       ? '?access_token=' + this.auth.getAccessToken()
@@ -104,4 +145,64 @@ export class VideoDownloadComponent {
   switchToType (type: DownloadType) {
     this.type = type
   }
+
+  getMetadataFormat (format: FfprobeFormat) {
+    const keyToTranslateFunction = {
+      'encoder': (value: string) => ({ label: this.i18n('Encoder'), value }),
+      'format_long_name': (value: string) => ({ label: this.i18n('Format name'), value }),
+      'size': (value: number) => ({ label: this.i18n('Size'), value: this.bytesPipe.transform(value, 2) }),
+      'bit_rate': (value: number) => ({
+        label: this.i18n('Bitrate'),
+        value: `${this.numbersPipe.transform(value)}bps`
+      })
+    }
+
+    // flattening format
+    const sanitizedFormat = Object.assign(format, format.tags)
+    delete sanitizedFormat.tags
+
+    return mapValues(
+      pick(sanitizedFormat, Object.keys(keyToTranslateFunction)),
+      (val, key) => keyToTranslateFunction[key](val)
+    )
+  }
+
+  getMetadataStream (streams: FfprobeStream[], type: 'video' | 'audio') {
+    const stream = streams.find(s => s.codec_type === type)
+    if (!stream) return undefined
+
+    let keyToTranslateFunction = {
+      'codec_long_name': (value: string) => ({ label: this.i18n('Codec'), value }),
+      'profile': (value: string) => ({ label: this.i18n('Profile'), value }),
+      'bit_rate': (value: number) => ({
+        label: this.i18n('Bitrate'),
+        value: `${this.numbersPipe.transform(value)}bps`
+      })
+    }
+
+    if (type === 'video') {
+      keyToTranslateFunction = Object.assign(keyToTranslateFunction, {
+        'width': (value: number) => ({ label: this.i18n('Resolution'), value: `${value}x${stream.height}` }),
+        'display_aspect_ratio': (value: string) => ({ label: this.i18n('Aspect ratio'), value }),
+        'avg_frame_rate': (value: string) => ({ label: this.i18n('Average frame rate'), value }),
+        'pix_fmt': (value: string) => ({ label: this.i18n('Pixel format'), value })
+      })
+    } else {
+      keyToTranslateFunction = Object.assign(keyToTranslateFunction, {
+        'sample_rate': (value: number) => ({ label: this.i18n('Sample rate'), value }),
+        'channel_layout': (value: number) => ({ label: this.i18n('Channel Layout'), value })
+      })
+    }
+
+    return mapValues(
+      pick(stream, Object.keys(keyToTranslateFunction)),
+      (val, key) => keyToTranslateFunction[key](val)
+    )
+  }
+
+  private hydrateMetadataFromMetadataUrl (file: VideoFile) {
+    const observable = this.videoService.getVideoFileMetadata(file.metadataUrl)
+    observable.subscribe(res => file.metadata = res)
+    return observable.toPromise()
+  }
 }
diff --git a/client/src/app/shared/video/video.service.ts b/client/src/app/shared/video/video.service.ts
index a51b9cab9..3aaf14990 100644
--- a/client/src/app/shared/video/video.service.ts
+++ b/client/src/app/shared/video/video.service.ts
@@ -32,6 +32,7 @@ import { UserSubscriptionService } from '@app/shared/user-subscription/user-subs
 import { VideoChannel } from '@app/shared/video-channel/video-channel.model'
 import { I18n } from '@ngx-translate/i18n-polyfill'
 import { NSFWPolicyType } from '@shared/models/videos/nsfw-policy.type'
+import { FfprobeData } from 'fluent-ffmpeg'
 
 export interface VideosProvider {
   getVideos (parameters: {
@@ -291,6 +292,14 @@ export class VideoService implements VideosProvider {
     return this.buildBaseFeedUrls(params)
   }
 
+  getVideoFileMetadata (metadataUrl: string) {
+    return this.authHttp
+               .get<FfprobeData>(metadataUrl)
+               .pipe(
+                 catchError(err => this.restExtractor.handleError(err))
+               )
+  }
+
   removeVideo (id: number) {
     return this.authHttp
                .delete(VideoService.BASE_VIDEO_URL + id)