use imChan0apGain to set spikeglx imec gain

Author: guptadivyansh

neo/rawio/spikeglxrawio.py

@@ -408,7 +408,10 @@ def extract_stream_info(meta_file, meta):
             # https://github.com/billkarsh/SpikeGLX/blob/15ec8898e17829f9f08c226bf04f46281f106e5f/Markdown/Metadata_30.md#imec
             # We allow also LF streams for NP2.0 because CatGT can produce them
             # See: https://github.com/SpikeInterface/spikeinterface/issues/1949
-            per_channel_gain[:-1] = 1 / 80.
+            if 'imChan0apGain' in meta:
+                per_channel_gain[:-1] = 1 / float(meta['imChan0apGain'])
+            else:
+                per_channel_gain[:-1] = 1 / 80.
             max_int = int(meta['imMaxInt']) if 'imMaxInt' in meta else 8192
             gain_factor = float(meta['imAiRangeMax']) / max_int
             channel_gains = gain_factor * per_channel_gain * 1e6