''' BVH Parser Class By Omid Alemi Created: June 12, 2017 Based on: https://gist.github.com/johnfredcee/2007503 ''' import re from unicodedata import name import numpy as np from .data import Joint, MocapData class BVHScanner(): ''' A wrapper class for re.Scanner ''' def __init__(self): def identifier(scanner, token): return 'IDENT', token def operator(scanner, token): return 'OPERATOR', token def digit(scanner, token): return 'DIGIT', token def open_brace(scanner, token): return 'OPEN_BRACE', token def close_brace(scanner, token): return 'CLOSE_BRACE', token self.scanner = re.Scanner([ (r'[a-zA-Z_]\w*', identifier), #(r'-*[0-9]+(\.[0-9]+)?', digit), # won't work for .34 #(r'[-+]?[0-9]*\.?[0-9]+', digit), # won't work for 4.56e-2 #(r'[-+]?[0-9]*\.?[0-9]+([eE][-+]?[0-9]+)?', digit), (r'-*[0-9]*\.?[0-9]+([eE][-+]?[0-9]+)?', digit), (r'}', close_brace), (r'}', close_brace), (r'{', open_brace), (r':', None), (r'\s+', None) ]) def scan(self, stuff): return self.scanner.scan(stuff) class BVHParser(): ''' A class to parse a BVH file. Extracts the skeleton and channel values ''' def __init__(self, filename=None): self.reset() def reset(self): self._skeleton = {} self.bone_context = [] self._motion_channels = [] self._motions = [] self.current_token = 0 self.framerate = 0.0 self.root_name = '' self.scanner = BVHScanner() self.data = MocapData() def parse(self, filename, start=0, stop=-1): self.reset() self.correct_row_num = 0 with open(filename, 'r') as f: for line in f.readlines(): self.correct_row_num += 1 with open(filename, 'r') as bvh_file: raw_contents = bvh_file.read() tokens, remainder = self.scanner.scan(raw_contents) self._parse_hierarchy(tokens) self.current_token = self.current_token + 1 self._parse_motion(tokens, start, stop) self.data.skeleton = self._skeleton self.data.channel_names = self._motion_channels self.data.values = self._to_DataFrame() self.data.root_name = self.root_name self.data.framerate = self.framerate return self.data def _to_DataFrame(self): '''Returns all of the channels parsed from the file as a pandas DataFrame''' import pandas as pd time_index = pd.to_timedelta([f[0] for f in self._motions], unit='s') frames = [f[1] for f in self._motions] channels = np.asarray([[channel[2] for channel in frame] for frame in frames]) column_names = ['%s_%s'%(c[0], c[1]) for c in self._motion_channels] return pd.DataFrame(data=channels, index=time_index, columns=column_names) def _new_bone(self, parent, name): bone = {'parent': parent, 'channels': [], 'offsets': [], 'order': '','children': []} return bone def _push_bone_context(self,name): self.bone_context.append(name) def _get_bone_context(self): return self.bone_context[len(self.bone_context)-1] def _pop_bone_context(self): self.bone_context = self.bone_context[:-1] return self.bone_context[len(self.bone_context)-1] def _read_offset(self, bvh, token_index): if bvh[token_index] != ('IDENT', 'OFFSET'): return None, None token_index = token_index + 1 offsets = [0.0] * 3 for i in range(3): offsets[i] = float(bvh[token_index][1]) token_index = token_index + 1 return offsets, token_index def _read_channels(self, bvh, token_index): if bvh[token_index] != ('IDENT', 'CHANNELS'): return None, None token_index = token_index + 1 channel_count = int(bvh[token_index][1]) token_index = token_index + 1 channels = [""] * channel_count order = "" for i in range(channel_count): channels[i] = bvh[token_index][1] token_index = token_index + 1 if(channels[i] == "Xrotation" or channels[i]== "Yrotation" or channels[i]== "Zrotation"): order += channels[i][0] else : order = "" return channels, token_index, order def _parse_joint(self, bvh, token_index): end_site = False joint_id = bvh[token_index][1] token_index = token_index + 1 joint_name = bvh[token_index][1] token_index = token_index + 1 parent_name = self._get_bone_context() if (joint_id == "End"): joint_name = parent_name+ '_Nub' end_site = True joint = self._new_bone(parent_name, joint_name) if bvh[token_index][0] != 'OPEN_BRACE': print('Was expecting brance, got ', bvh[token_index]) return None token_index = token_index + 1 offsets, token_index = self._read_offset(bvh, token_index) joint['offsets'] = offsets if not end_site: channels, token_index, order = self._read_channels(bvh, token_index) joint['channels'] = channels joint['order'] = order for channel in channels: self._motion_channels.append((joint_name, channel)) self._skeleton[joint_name] = joint self._skeleton[parent_name]['children'].append(joint_name) while (bvh[token_index][0] == 'IDENT' and bvh[token_index][1] == 'JOINT') or (bvh[token_index][0] == 'IDENT' and bvh[token_index][1] == 'End'): self._push_bone_context(joint_name) token_index = self._parse_joint(bvh, token_index) self._pop_bone_context() if bvh[token_index][0] == 'CLOSE_BRACE': return token_index + 1 print('Unexpected token ', bvh[token_index]) def _parse_hierarchy(self, bvh): self.current_token = 0 if bvh[self.current_token] != ('IDENT', 'HIERARCHY'): return None self.current_token = self.current_token + 1 if bvh[self.current_token] != ('IDENT', 'ROOT'): return None self.current_token = self.current_token + 1 if bvh[self.current_token][0] != 'IDENT': return None root_name = bvh[self.current_token][1] root_bone = self._new_bone(None, root_name) self.current_token = self.current_token + 2 #skipping open brace offsets, self.current_token = self._read_offset(bvh, self.current_token) channels, self.current_token, order = self._read_channels(bvh, self.current_token) root_bone['offsets'] = offsets root_bone['channels'] = channels root_bone['order'] = order self._skeleton[root_name] = root_bone self._push_bone_context(root_name) for channel in channels: self._motion_channels.append((root_name, channel)) while bvh[self.current_token][1] == 'JOINT': self.current_token = self._parse_joint(bvh, self.current_token) self.root_name = root_name def _parse_motion(self, bvh, start, stop): if bvh[self.current_token][0] != 'IDENT': print('Unexpected text') return None if bvh[self.current_token][1] != 'MOTION': print('No motion section') return None self.current_token = self.current_token + 1 if bvh[self.current_token][1] != 'Frames': return None self.current_token = self.current_token + 1 frame_count = int(bvh[self.current_token][1]) if stop<0 or stop>frame_count: stop = min(frame_count, self.correct_row_num-431) assert(start>=0) assert(start=start: self._motions[idx] = (frame_time, channel_values) frame_time = frame_time + frame_rate idx+=1 if __name__ == "__main__": p = BVHParser() data = [p.parse("../../../datasets/beat_full/2/2_scott_0_1_1.bvh")]