feat: complete implementation using gemini as analyzer

src/StreamShorts.Library/Analysis/Gemini/GeminiAnalyzer.cs

@@ -12,61 +12,68 @@ namespace StreamShorts.Library.Analysis.Gemini;
 /// <inheritdoc/>
 public sealed class GeminiAnalyzer(
   IHttpClientFactory httpClientFactory,
-  string apiKey
-  ) : ITranscriptAnalyzer
+  string apiKey,
+  string? model = null
+) : ITranscriptAnalyzer
 {
-  private readonly IHttpClientFactory _httpClientFactory = httpClientFactory ?? throw new ArgumentNullException(nameof(httpClientFactory));
+  private readonly IHttpClientFactory _httpClientFactory =
+    httpClientFactory ?? throw new ArgumentNullException(nameof(httpClientFactory));
+
   private readonly string _apiKey = apiKey ?? throw new ArgumentNullException(nameof(apiKey));
+  private readonly string _model = model ?? "gemini-2.5-flash-lite";
   private readonly IAnalysisPrompt _prompt = new DefaultAnalysisPrompt();
 
   public GeminiAnalyzer(
     IHttpClientFactory httpClientFactory,
     string apiKey,
-    IAnalysisPrompt prompt
-  ) : this(httpClientFactory, apiKey)
+    IAnalysisPrompt prompt,
+    string? model = null
+  ) : this(httpClientFactory, apiKey, model)
   {
     _prompt = prompt ?? throw new ArgumentNullException(nameof(prompt));
   }
 
   public async Task<TranscriptAnalysis> AnalyzeAsync(IEnumerable<TranscriptionSegment> segments)
   {
-    using var client = _httpClientFactory.CreateClient();
-    client.Timeout = TimeSpan.FromMinutes(5);
-
-    var requestUrl = $"https://generativelanguage.googleapis.com/v1beta/models/gemini-2.5-flash-lite:generateContent?key={_apiKey}";
-    var generateContentRequest = new GenerateContentRequest(
-      [
-        new Content(
-          Role: "user",
-          Parts:[ new Part(Text: _prompt.GetPrompt(segments)) ]
-        )
-      ],
-      new GenerationConfig(ResponseMimeType: "application/json")
-    );
-    using var requestContent = new StringContent(
-      JsonSerializer.Serialize(generateContentRequest),
-      Encoding.UTF8,
-      "application/json"
-    );
-    using var request = new HttpRequestMessage(HttpMethod.Post, requestUrl)
+    try
     {
-      Content = requestContent
-    };
+      using var client = _httpClientFactory.CreateClient();
+      client.Timeout = TimeSpan.FromMinutes(5);
 
-    var response = await client.SendAsync(request).ConfigureAwait(false);
-    var responseContent = await response.Content.ReadAsStringAsync().ConfigureAwait(false);
-    var responseJson = JsonSerializer.Deserialize<GenerateContentResponse>(responseContent);
-    var candidatesText = responseJson?
-      .Candidates?
-      .FirstOrDefault()?
-      .Content
-      .Parts?.FirstOrDefault()?
-      .Text;
+      var requestUrl =
+        $"https://generativelanguage.googleapis.com/v1beta/models/{_model}:generateContent?key={_apiKey}";
+      var generateContentRequest = new GenerateContentRequest(
+        [
+          new Content(
+            Role: "user",
+            Parts: [new Part(Text: _prompt.GetPrompt(segments))]
+          )
+        ],
+        new GenerationConfig(ResponseMimeType: "application/json")
+      );
+      using var requestContent = new StringContent(
+        JsonSerializer.Serialize(generateContentRequest),
+        Encoding.UTF8,
+        "application/json"
+      );
+      using var request = new HttpRequestMessage(HttpMethod.Post, requestUrl) { Content = requestContent };
 
-    var clips = JsonSerializer.Deserialize<List<ShortCandidate>>(candidatesText ?? string.Empty);
-    return new TranscriptAnalysis(clips ?? []);
+      var response = await client.SendAsync(request).ConfigureAwait(false);
+      var responseContent = await response.Content.ReadAsStringAsync().ConfigureAwait(false);
+      var responseJson = JsonSerializer.Deserialize<GenerateContentResponse>(responseContent);
+      var candidatesText = responseJson?
+        .Candidates?
+        .FirstOrDefault()?
+        .Content
+        .Parts?.FirstOrDefault()?
+        .Text;
+
+      var clips = JsonSerializer.Deserialize<List<ShortCandidate>>(candidatesText ?? string.Empty);
+      return new TranscriptAnalysis(clips ?? []);
+    }
+    catch (Exception e)
+    {
+      throw new FailedTranscriptAnalysisException("Failed to analyze transcript segments using Gemini.", e);
+    }
   }
-}
-
-
-
+}

src/StreamShorts.Library/Analysis/ITranscriptAnalyzer.cs

@@ -11,6 +11,7 @@ public interface ITranscriptAnalyzer
   /// Analyzes the provided transcript segments and generates a transcript analysis result.
   /// </summary>
   /// <param name="segments">The transcript segments to analyze.</param>
-  /// <returns>A task that represents the asynchronous operation. The task result contains the <see cref="TranscriptAnalysis"/> containing the short clips derived from the transcript.</returns> 
+  /// <returns>A task that represents the asynchronous operation. The task result contains the <see cref="TranscriptAnalysis"/> containing the short clips derived from the transcript.</returns>
+  /// <exception cref="FailedTranscriptAnalysisException">Thrown when the analysis fails due to an error.</exception>
   Task<TranscriptAnalysis> AnalyzeAsync(IEnumerable<TranscriptionSegment> segments);
 }

src/StreamShorts.Library/Analysis/Prompts/DefaultAnalysisPrompt.cs

@@ -42,8 +42,9 @@ internal sealed class DefaultAnalysisPrompt : IAnalysisPrompt
   {0}
   ");
 
-  public string GetPrompt(IEnumerable<TranscriptionSegment> transcript)
+  public string GetPrompt(IEnumerable<TranscriptionSegment> segments)
   {
+    var transcript = string.Join(Environment.NewLine, segments);
     return string.Format(CultureInfo.InvariantCulture, Prompt, transcript);
   }
 }

src/StreamShorts.Library/Media/FFMpegService.cs

@@ -1,4 +1,3 @@
-
 using FFMpegCore;
 using FFMpegCore.Enums;
 using FFMpegCore.Pipes;
@@ -23,19 +22,18 @@ internal sealed class FFMpegService : IVideoService
       .ConfigureAwait(false);
   }
 
-  public async Task<Stream> ExtractClipFromVideoAsync(Stream video, TimeSpan start, TimeSpan end, TimeSpan? buffer = null)
+  public async Task CreateClipFromVideoAsync(
+    string sourcePath, 
+    string destinationPath, 
+    TimeSpan startTime,
+    TimeSpan endTime,
+    TimeSpan? buffer = null
+  )
   {
-    var startTime = start - (buffer ?? TimeSpan.Zero);
-    var endTime = end + (buffer ?? TimeSpan.Zero);
-    var outputStream = new MemoryStream();
-
-    await FFMpegArguments
-      .FromPipeInput(new StreamPipeSource(video), o => o.Seek(startTime).EndSeek(endTime))
-      .OutputToPipe(new StreamPipeSink(outputStream), o => o.CopyChannel().ForceFormat("webm"))
-      .ProcessAsynchronously()
+    var start = startTime - (buffer ?? TimeSpan.Zero);
+    var end = endTime + (buffer ?? TimeSpan.Zero);
+    
+    await FFMpeg.SubVideoAsync(sourcePath, destinationPath, start, end)
       .ConfigureAwait(false);
-
-    outputStream.Position = 0;
-    return outputStream;
   }
 }

src/StreamShorts.Library/Media/IVideoService.cs

@@ -12,14 +12,21 @@ internal interface IVideoService
   /// <param name="audio">The output audio stream.</param>
   /// <returns>A task that represents the asynchronous operation. The task result indicates whether the extraction was successful.</returns>
   Task<bool> ExtractAudioFromVideoAsync(Stream video, Stream audio);
-
+  
   /// <summary>
-  /// Extracts a clip from a video stream.
+  /// Creates a clip from a video file based on the specified start and end times.
   /// </summary>
-  /// <param name="video">The input video stream.</param>
-  /// <param name="start">The start time of the clip.</param>
-  /// <param name="end">The end time of the clip.</param>
-  /// <param name="buffer">The duration of the buffer to include before the start time and after the end time.</param>
-  /// <returns>A task that represents the asynchronous operation. The task result contains the extracted clip as a stream.</returns>
-  Task<Stream> ExtractClipFromVideoAsync(Stream video, TimeSpan start, TimeSpan end, TimeSpan? buffer = null);
+  /// <param name="sourcePath">The path to the source video file.</param>
+  /// <param name="destinationPath">The path where the created clip will be saved.</param>
+  /// <param name="startTime">The start time of the clip.</param>
+  /// <param name="endTime">The end time of the clip.</param>
+  /// <param name="buffer">An optional buffer time to include before and after the clip segment.</param>
+  /// <returns>A task that represents the asynchronous operation.</returns>
+  Task CreateClipFromVideoAsync(
+    string sourcePath,
+    string destinationPath,
+    TimeSpan startTime,
+    TimeSpan endTime,
+    TimeSpan? buffer = null
+  );
 }

src/StreamShorts.Library/Media/Video/IShortsCreator.cs

@@ -8,13 +8,14 @@ namespace StreamShorts.Library.Media.Video;
 public interface IShortsCreator
 {
   /// <summary>
-  /// Creates video shorts from the provided transcript analysis and video stream.
+  /// Creates a video short from the specified source video file based on the provided candidate details.
   /// </summary>
-  /// <param name="analysis">The transcript analysis.</param>
-  /// <param name="video">The video stream.</param>
-  /// <param name="buffer">An optional buffer duration to include before the start time and after the end time of each short.</param>
-  /// <returns>An asynchronous enumerable of <see cref="ShortClip"/>.</returns>
-  /// <exception cref="ArgumentNullException">Thrown when <paramref name="analysis"/> is null.</exception>
-  /// <exception cref="ArgumentNullException">Thrown when <paramref name="video"/> is null.</exception>
-  public IAsyncEnumerable<ShortClip> CreateShortsAsync(TranscriptAnalysis analysis, Stream video, TimeSpan? buffer = null);
+  /// <param name="sourcePath">The path to the source video file.</param>
+  /// <param name="candidate">The details of the short candidate.</param>
+  /// <param name="destinationPath">The path where the created short will be saved.</param>
+  /// <param name="buffer">An optional buffer time to include before and after the short segment.</param>
+  /// <returns>A task that represents the asynchronous operation.</returns>
+  /// <exception cref="ArgumentNullException">Thrown when <paramref name="sourcePath"/> or <paramref name="destinationPath"/> is null or whitespace.</exception>
+  /// <exception cref="ArgumentNullException">Thrown when <paramref name="candidate"/> is null.</exception>
+  public Task CreateShortAsync(string sourcePath, ShortCandidate candidate, string destinationPath, TimeSpan? buffer = null);
 }

src/StreamShorts.Library/Media/Video/ShortClip.cs

@@ -1,11 +0,0 @@
-using StreamShorts.Library.Analysis;
-
-namespace StreamShorts.Library.Media.Video;
-
-/// <summary>
-/// Represents a short video clip.
-/// </summary>
-public record ShortClip(
-  ShortCandidate Candidate,
-  Stream Segment
-);

src/StreamShorts.Library/Media/Video/ShortsCreator.cs

@@ -19,27 +19,24 @@ public class ShortsCreator : IShortsCreator
     _videoService = videoService ?? throw new ArgumentNullException(nameof(videoService), $"{nameof(videoService)} cannot be null");
   }
 
-  public async IAsyncEnumerable<ShortClip> CreateShortsAsync(TranscriptAnalysis analysis, Stream video, TimeSpan? buffer = null)
+  public async Task CreateShortAsync(string sourcePath, ShortCandidate candidate, string destinationPath, TimeSpan? buffer = null)
   {
-    if (analysis is null)
+    if (string.IsNullOrWhiteSpace(sourcePath))
     {
-      throw new ArgumentNullException(nameof(analysis), $"{nameof(analysis)} cannot be null");
+      throw new ArgumentNullException(nameof(sourcePath), $"{nameof(sourcePath)} cannot be null or whitespace");
     }
-
-    if (video is null)
+    
+    if (candidate is null)
     {
-      throw new ArgumentNullException(nameof(video), $"{nameof(video)} cannot be null");
+      throw new ArgumentNullException(nameof(candidate), $"{nameof(candidate)} cannot be null");
     }
-
-    foreach (var candidate in analysis.Candidates)
+    
+    if (string.IsNullOrWhiteSpace(destinationPath))
     {
-      var clip = await _videoService.ExtractClipFromVideoAsync(video, candidate.StartTime, candidate.EndTime, buffer)
-        .ConfigureAwait(false);
-
-      yield return new ShortClip(
-        candidate,
-        clip
-      );
+      throw new ArgumentNullException(nameof(destinationPath), $"{nameof(destinationPath)} cannot be null or whitespace");
     }
+    
+    await _videoService.CreateClipFromVideoAsync(sourcePath, destinationPath, candidate.StartTime, candidate.EndTime, buffer)
+      .ConfigureAwait(false);
   }
 }

src/StreamShorts.Library/Transcription/FailedAudioTranscriptionException.cs

@@ -1,31 +0,0 @@
-namespace StreamShorts.Library.Transcription;
-
-/// <summary>
-/// Represents an error that occurs when audio transcription fails.
-/// </summary>
-public sealed class FailedAudioTranscriptionException : Exception
-{
-  /// <summary>
-  /// Initializes a new instance of the <see cref="FailedAudioTranscriptionException"/> class with no parameters.
-  /// </summary>
-  public FailedAudioTranscriptionException()
-  {
-  }
-
-  /// <summary>
-  /// Initializes a new instance of the <see cref="FailedAudioTranscriptionException"/> class with a specified error message.
-  /// </summary>
-  /// <param name="message">The error message that explains the reason for the exception.</param>
-  public FailedAudioTranscriptionException(string message) : base(message)
-  {
-  }
-
-  /// <summary>
-  /// Initializes a new instance of the <see cref="FailedAudioTranscriptionException"/> class with a specified error message and a reference to the inner exception that is the cause of this exception.
-  /// </summary>
-  /// <param name="message">The error message that explains the reason for the exception.</param>
-  /// <param name="innerException">The exception that is the cause of the current exception.</param>
-  public FailedAudioTranscriptionException(string message, Exception innerException) : base(message, innerException)
-  {
-  }
-}

src/StreamShorts.Library/Transcription/TranscriptionSegment.cs

@@ -10,4 +10,10 @@ public sealed record TranscriptionSegment(
   TimeSpan StartTime,
   TimeSpan EndTime,
   string Text
-);
+)
+{
+  public override string ToString()
+  {
+    return $"[{StartTime:hh\\:mm\\:ss} - {EndTime:hh\\:mm\\:ss}]: {Text}";
+  }
+}