---
title: Multi-Clip Concatenation
url: https://docs.kaltura.com/docs/rich-media-cms-apis/content-management/video-editing-multi-clip-concatenation
---

## Multi-Clip Concatenation


Splice segments from multiple source entries into a single output.

### Basic Concatenation (Two Sources)


```bash
curl -X POST "$KALTURA_SERVICE_URL/service/media/action/addContent" \
  -d "ks=$KALTURA_KS" \
  -d "format=1" \
  -d "entryId=$KALTURA_ENTRY_ID" \
  -d "resource[objectType]=KalturaOperationResources" \
  -d "resource[resources][0][objectType]=KalturaOperationResource" \
  -d "resource[resources][0][resource][objectType]=KalturaEntryResource" \
  -d "resource[resources][0][resource][entryId]=$KALTURA_SOURCE_ENTRY_1" \
  -d "resource[resources][0][resource][flavorParamsId]=0" \
  -d "resource[resources][0][operationAttributes][0][objectType]=KalturaClipAttributes" \
  -d "resource[resources][0][operationAttributes][0][offset]=0" \
  -d "resource[resources][0][operationAttributes][0][duration]=10000" \
  -d "resource[resources][1][objectType]=KalturaOperationResource" \
  -d "resource[resources][1][resource][objectType]=KalturaEntryResource" \
  -d "resource[resources][1][resource][entryId]=$KALTURA_SOURCE_ENTRY_2" \
  -d "resource[resources][1][resource][flavorParamsId]=0" \
  -d "resource[resources][1][operationAttributes][0][objectType]=KalturaClipAttributes" \
  -d "resource[resources][1][operationAttributes][0][offset]=0" \
  -d "resource[resources][1][operationAttributes][0][duration]=15000"
```


Output: a new entry with first 10s of source 1 followed by first 15s of source 2.

### Chapter Name Policy

When concatenating clips, Kaltura can auto-generate chapter cue points. Control naming with `chapterNamePolicy`:

| Value | Policy | Chapter Names |
|-------|--------|---------------|
| 1 | BY_ENTRY_ID | Source entry IDs as chapter titles |
| 2 | BY_ENTRY_NAME | Source entry names as chapter titles |
| 3 | NUMERICAL | Sequential numbers (1, 2, 3...) |

Add to the request:


```bash
  -d "resource[chapterNamePolicy]=2"
```


### Global Offset in Destination

Use `globalOffsetInDestination` (milliseconds) on each clip to control placement timing in the output timeline. Gaps between clips result in black frames.


```bash
  -d "resource[resources][0][operationAttributes][0][globalOffsetInDestination]=0" \
  -d "resource[resources][1][operationAttributes][0][globalOffsetInDestination]=15000"
```


### Dimension Normalization

When concatenating sources with different resolutions, use `dimensionsAttributes` on the `KalturaOperationResources` container to normalize output dimensions.

**Crop to aspect ratio:**


```bash
  -d "resource[dimensionsAttributes][objectType]=KalturaAspectRatioCropAttributes" \
  -d "resource[dimensionsAttributes][aspectRatioX]=16" \
  -d "resource[dimensionsAttributes][aspectRatioY]=9"
```


**Scale with letterbox/pillarbox:**


```bash
  -d "resource[dimensionsAttributes][objectType]=KalturaAspectRatioScaleAttributes" \
  -d "resource[dimensionsAttributes][aspectRatioX]=16" \
  -d "resource[dimensionsAttributes][aspectRatioY]=9"
```


**Exact resolution crop:**


```bash
  -d "resource[dimensionsAttributes][objectType]=KalturaResolutionCropAttributes" \
  -d "resource[dimensionsAttributes][width]=1920" \
  -d "resource[dimensionsAttributes][height]=1080"
```