# Camera access / Chunk data access with IDS camera **URL:** \ **Category:** Programming Questions\ **Tags:** acquisition, python\ **Created:** [July 30, 2025, 9:58am UTC](https://forum.commonvisionblox.com/t/camera-access-chunk-data-access-with-ids-camera/2437 "2025-07-30T09:58:00Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![mmuhieddine](https://avatars.discourse-cdn.com/v4/letter/m/cdc98d/32.png) [@mmuhieddine](https://forum.commonvisionblox.com/u/mmuhieddine)\ **Post date:** [July 30, 2025, 9:58am UTC](https://forum.commonvisionblox.com/t/camera-access-chunk-data-access-with-ids-camera/2437/1 "2025-07-30T09:58:00Z")
**Hello !** I’m trying to update our software to support IDS camera (GV-527xCP-C). We already support Flir-Teledyne and Lucid Vision cameras. We are using CVB 14.00.008. (We also tried CVB 14.01.006) on Nvidia Jetson. IDS Camera has the latest firmware installed. We both use C++ API and python bindings depending on purpose (production or calibration). We installed ids-peak package to get the correct cti files. After installing version 2.17, the `GENICAM_GENTL64_PATH` is updated to `/usr/lib/ids/cti` ```bash Lucid camera are not detected anymore (make sense). IDS are still detected but can’t be opened anymore:Traceback (most recent call last): File "/home/nvidia/workspace/platform/edge/test_ids_chunk_issue.py", line 18, in with cvb.DeviceFactory.open( RuntimeError: Unspecified GenTL error ``` Reverting the `GENICAM_GENTL64_PATH` to `GENICAM_GENTL64_PATH=/opt/cvb/drivers/genicam`, we can open the camera. When Chunk Mode is deactivated, image acquisition works just fine : Set Node Std::ChunkModeActive to false - Composite purpose is Image - First item type is cvb.Image - Access the image from the composite object ```auto Number of parts: 1, purpose: 0 First part type: Trying to convert to MultiPartImage Size of image: 1536.0, 2048.0 ``` When Chunk Mode is activated, it doesn’t work: Set Node `Std::ChunkModeActive` and `Std::ChunkEnable[Std::ChunkSelector(Timestamp)]` to true - Composite purpose is custom - First item type is NoneType - ChunkTimestamp node is not readable ```bash Number of parts: 1, purpose: -1 First part type: Trying to convert to MultiPartImage Size of image: 0.0, 0.0 Traceback (most recent call last): File "/usr/app/test_ids_chunk_issue.py", line 18, in with cvb.DeviceFactory.open( File "/usr/app/test_ids_chunk_issue.py", line 47, in print(f"Chunk timestamp: {chunk_timestamp_node.value}") RuntimeError: Node is not readable. ``` It also works fine with the default CVB `GENICAM_GENTL64_PATH` for Lucid Cameras: ```auto Number of parts: 1, purpose: 0 First part type: Trying to convert to MultiPartImage Size of image: 1536.0, 2048.0 Chunk timestamp: 61804137122696 ``` I think it’s related to the cti file (tbc?) Based on what I read on this forum and in the documentation, I briefly tried to use the solution by using `PFNCBuffer` but it didn’t work. I didn’t investigate more this solution because when I try to access the camera through GenICamBrowser (using the`GENICAM_GENTL64_PATH=/usr/lib/ids/cti` ), everything works ! Even setting the ChunkMode works, the ChunkTimestamp Node is readable and visible. So I wanted to know why it’s working fine with GenICamBrowser but not with the python script (or cpp script) ? Here is the small script I use for test : ```python import cvb from typing import Optional, Tuple if __name__ == " __main__": exp_serial_num = "4108794564" exp_device = None devices = cvb.DeviceFactory.discover_from_root(flags=cvb.DiscoverFlags.IgnoreVins) for device in devices: if device.read_property(cvb.DiscoveryProperties.DeviceSerialNumber) == exp_serial_num: exp_device = device break if exp_device is None: raise ValueError("Device not found") exp_device.set_parameter("AttachChunk","1") print(f"token: {exp_device.access_token}") with cvb.DeviceFactory.open( provider=exp_device.access_token, acquisition_stack=cvb.AcquisitionStack.GenTL ) as exp_device_ptr: node_map = exp_device_ptr.node_maps[cvb.NodeMapID.Device] # Chunk mode active chunk_mode_active = node_map["Std::ChunkModeActive"] chunk_mode_active.from_string("1") #chunk_selector = node_map["Std::ChunkSelector"] #chunk_selector.from_string("Timestamp") #chunk_enable = node_map["Std::ChunkEnable"] #chunk_enable.from_string("1") # grab stream: Optional[cvb.CompositeStream] = exp_device_ptr.stream(stream_type=cvb.CompositeStream) stream.start() result: Tuple[Optional[cvb.Composite], int, Optional[cvb.NodeMapEnumerator]] = stream.wait_for( time_span=1000 ) composite, status, _ = result if status == cvb.WaitStatus.Ok: print(f"Number of parts: {composite.item_count}, purpose: {composite.purpose}") print(f"First part type: {type(composite[0])}") try: print("Trying to convert to MultiPartImage") img :cvb.MultiPartImage = cvb.MultiPartImage.from_composite(composite) print(f"Size of image: {img.size.height}, {img.size.width}") except Exception as e: print(f"Error: {e}") chunk_timestamp_node = node_map["Std::ChunkTimestamp"] print(f"Chunk timestamp: {chunk_timestamp_node.value}") stream.stop() ``` ---
**Author:** ![Sebastian](https://yyz1.discourse-cdn.com/flex027/user_avatar/forum.commonvisionblox.com/sebastian/32/1267_2.png) [@Sebastian](https://forum.commonvisionblox.com/u/Sebastian)\ **Post date:** [July 31, 2025, 11:07am UTC](https://forum.commonvisionblox.com/t/camera-access-chunk-data-access-with-ids-camera/2437/2 "2025-07-31T11:07:25Z")
Hi @mmuhieddine , **IDS TL Issue** Currently, i do not see why the IDS TL works in the GenICam Browser but not within the CVB code. Based on your description I would have expected an issue related to the IDS TL. But then it should not work with the GenICam Browser as well. **Chunk data access with our TL** As it works with the Lucid camera we probably have not a general issue. Maybe there is another difference between your Lucid camera and your IDS camera which influences the acquisition, like the Pixel Format. Which PixelFormats are you using for tests. ---
**Author:** ![mmuhieddine](https://avatars.discourse-cdn.com/v4/letter/m/cdc98d/32.png) [@mmuhieddine](https://forum.commonvisionblox.com/u/mmuhieddine)\ **Post date:** [July 31, 2025, 12:32pm UTC](https://forum.commonvisionblox.com/t/camera-access-chunk-data-access-with-ids-camera/2437/3 "2025-07-31T12:32:35Z")
Hi @Sebastian Thanks for your reply. I agree with your statement, if it was from the IDS TL, it shouldn’t even work with GenICamBrowser. That’s why I think I’m missing something here. We use the same configuration for both Lucid and IDS cameras, which include Pixel Format BayerRG8. ---
**Author:** ![Chris](https://yyz1.discourse-cdn.com/flex027/user_avatar/forum.commonvisionblox.com/chris/32/1154_2.png) [@Chris](https://forum.commonvisionblox.com/u/Chris)\ **Post date:** [August 4, 2025, 1:30pm UTC](https://forum.commonvisionblox.com/t/camera-access-chunk-data-access-with-ids-camera/2437/4 "2025-08-04T13:30:01Z")
Hi @mmuhieddine , I would kindly ask you to contact our support department for this topic: [https://www.stemmer-imaging.com/our-services/customer-services/support?redirect=false](https://www.stemmer-imaging.com/our-services/customer-services/support?redirect=false) I think this needs some clarification that might involve further testing on our side. As we are working with third party vendors/TLs here, we might very likely have an issue with the standard not being fulfilled 100%. Unfortunately this happens from time to time but in order for you to get a working solution as fast as possible, our regular support might be the best way to continue from here. Cheers Chris ---
**Author:** ![mmuhieddine](https://avatars.discourse-cdn.com/v4/letter/m/cdc98d/32.png) [@mmuhieddine](https://forum.commonvisionblox.com/u/mmuhieddine)\ **Post date:** [August 5, 2025, 8:04am UTC](https://forum.commonvisionblox.com/t/camera-access-chunk-data-access-with-ids-camera/2437/5 "2025-08-05T08:04:46Z")
Hi @Chris, I will contact your support department then and keep this topic up-to-date if anything new pops up. Thanks for your help, Marin