web/backend/api/info.py

@@ -5,7 +5,12 @@ from fastapi import APIRouter, HTTPException
 from backend.config import settings
 from backend.services.file_manager import FileManager
 from backend.services.task_manager import task_manager
-from backend.ffmpeg import get_stream_info
+
+# Import core functions
+from audio_splitter.ffmpeg import get_stream_info, get_container_format, get_audio_codec
+from audio_splitter.formats import determine_default_format
+from audio_splitter.constants import FORMAT_INFO
+from audio_splitter.defaults import DEFAULT_FORMAT
 
 router = APIRouter(prefix="/api", tags=["info"])
 
@@ -13,7 +18,8 @@ router = APIRouter(prefix="/api", tags=["info"])
 @router.get("/info/{task_id}")
 async def get_task_info(task_id: str):
     """
-    Return stream information (has_audio, has_video, has_subtitle) for the uploaded file.
+    Return stream information (has_audio, has_video, has_subtitle, audio_codec)
+    for the uploaded file.
     """
     if not task_manager.has_task(task_id):
         raise HTTPException(status_code=404, detail=f"Task {task_id} not found")
@@ -33,3 +39,34 @@ async def get_task_info(task_id: str):
         }
     except Exception as e:
         raise HTTPException(status_code=500, detail=f"Failed to retrieve stream info: {str(e)}")
+
+
+@router.get("/info/recommended-format/{task_id}")
+async def get_recommended_format(task_id: str):
+    """
+    Return the recommended output format (container name) for the uploaded file,
+    based on its container and audio codec.
+    """
+    if not task_manager.has_task(task_id):
+        raise HTTPException(status_code=404, detail=f"Task {task_id} not found")
+
+    input_path = FileManager.get_input_path(task_id)
+    if not input_path or not input_path.exists():
+        raise HTTPException(status_code=404, detail="Input file not found")
+
+    try:
+        container = get_container_format(str(input_path))
+        codec = get_audio_codec(str(input_path))
+
+        fmt = determine_default_format(container, codec)
+
+        # Fallback if detection fails or format is unsupported
+        if fmt is None:
+            fmt = DEFAULT_FORMAT
+        if fmt not in FORMAT_INFO:
+            fmt = "mp3"  # ultimate fallback
+
+        return {"format": fmt}
+
+    except Exception as e:
+        raise HTTPException(status_code=500, detail=f"Failed to determine format: {str(e)}")

web/frontend/src/api/client.ts

@@ -63,3 +63,8 @@ export const getTaskInfo = async (task_id: string): Promise<{
   const response = await api.get(`/info/${task_id}`)
   return response.data
 }
+
+export const getRecommendedFormat = async (task_id: string): Promise<{ format: string }> => {
+  const response = await api.get(`/info/recommended-format/${task_id}`)
+  return response.data
+}

web/frontend/src/components/UploadZone.tsx

@@ -3,7 +3,8 @@ import { useDropzone } from 'react-dropzone'
 import { Box, Typography, Paper, LinearProgress, Alert } from '@mui/material'
 import { CloudUpload, InsertDriveFile } from '@mui/icons-material'
 import { useUploadStore } from '../stores/uploadStore'
-import { uploadFile, getTaskInfo } from '../api/client'
+import { useOptionsStore } from '../stores/optionsStore'  // NEW
+import { uploadFile, getTaskInfo, getRecommendedFormat } from '../api/client'  // NEW
 import { useTaskStore } from '../stores/taskStore'
 
 const ALLOWED_EXTENSIONS = ['.mp3', '.flac', '.wav', '.m4a', '.ogg', '.opus', '.aac', '.wma', '.aiff', '.alac', '.ac3']
@@ -30,6 +31,7 @@ export const UploadZone: React.FC = () => {
   } = useUploadStore()
 
   const { setTaskId: setTaskIdStore } = useTaskStore()
+  const { setOptions } = useOptionsStore()   // NEW
 
   const onDrop = useCallback(
     async (acceptedFiles: File[]) => {
@@ -65,9 +67,18 @@ export const UploadZone: React.FC = () => {
           setHasAudio(info.has_audio)
           setHasSubtitle(info.has_subtitle)
           setAudioCodec(info.audio_codec)
+
+          // Fetch recommended format and update options
+          try {
+            const rec = await getRecommendedFormat(taskId)
+            // Update only the format; keep other options (e.g., transcode_to) as defaults
+            setOptions({ format: rec.format })
+          } catch (err) {
+            console.warn('Failed to fetch recommended format, using default', err)
+          }
         } catch (err) {
           console.error('Failed to fetch stream info:', err)
-          // Don't block the upload flow if this fails; we'll just assume no video
+          // Don't block upload flow; user can manually change options
         }
       } catch (err: any) {
         setError(err.response?.data?.detail || err.message || 'Upload failed')
@@ -78,7 +89,7 @@ export const UploadZone: React.FC = () => {
         setFileSize(0)
       }
     },
-    [setFile, setFileName, setFileSize, setIsUploading, setUploadProgress, setError, setTaskId, setTaskIdStore]
+    [setFile, setFileName, setFileSize, setIsUploading, setUploadProgress, setError, setTaskId, setTaskIdStore, setHasVideo, setHasAudio, setHasSubtitle, setAudioCodec, setOptions]
   )
 
   const { getRootProps, getInputProps, isDragActive } = useDropzone({