fixed a bug and added notes to spec per discussion

README.md

@@ -51,9 +51,9 @@ pip install .
 ```python
 import sigmf
 handle = sigmf.sigmffile.fromfile('example.sigmf')
-handle.read_samples() # returns timeseries data
-handle.get_global_info() # returns 'global' metadata dictionary
-handle.get_captures() # returns 'captures' metadata dictionary
+handle.read_samples() # returns all timeseries data
+handle.get_global_info() # returns 'global' dictionary
+handle.get_captures() # returns list of 'captures' dictionaries
 handle.get_annotations() # returns list of all annotations
 ```
 

sigmf-spec.md

@@ -185,9 +185,15 @@ dataset file MUST NOT contain any other characters (e.g., delimiters,
 whitespace, line-endings, `EOF` characters, etc.,).
 
 Complex samples should be interleaved, with the in-phase component first (i.e.,
-`I[0]` `Q[0]` `I[1]` `Q[1]` ... `I[n]` `Q[n]`).  Also note that the `type`
-applies to not only the real but also the imaginary component of a complex
-sample.
+`I[0]` `Q[0]` `I[1]` `Q[1]` ... `I[n]` `Q[n]`). When `core:num_channels` in the
+`global` object indicates that the recording contains more than one channel,
+samples from those channels should be interleaved in the same manner, with
+the same index from each channel's sample serially in the recording. For
+example, a recording with two channels of `i16_le` representing real-valued
+audio data from a stereo recording and here labeled `L` for left and `R` for
+right, the data should appear as `L[0]` `R[0]` `L[1]` `R[1]` ... `L[n]` `R[n]`.
+The data type specified by `core:data_type` applies to all channels of data
+both real and imaginary parts.
 
 ### Metadata Format
 

sigmf/sigmffile.py

@@ -277,8 +277,8 @@ def _count_samples(self):
             sample_size = self.get_sample_size()
             num_channels = self.get_num_channels()
             sample_count = file_size // sample_size // num_channels
-            if file_size % sample_size != 0:
-                warnings.warn("File '{}' does not contain an integral number of sample. It might not be valid data.".format(self.data_file))
+            if file_size % sample_count != 0:
+                warnings.warn("File '{}' does not contain an integer number of samples. It may be invalid data.".format(self.data_file))
             if len(annotations) > 0 and annotations[-1][self.START_INDEX_KEY] + annotations[-1][self.LENGTH_INDEX_KEY] > sample_count:
                 warnings.warn("File '{}' ends before the final annotation in the corresponding SigMF metadata.".format(self.data_file))
         self.sample_count = sample_count