Fix button parser

igstools/parser.py

@@ -1,53 +1,24 @@
 # References:
 # Muxer/Demuxer: http://patches.libav.org/patch/22445/
 # Decoder:       http://patches.libav.org/patch/22446/
-import struct
+
 import io
 import logging
+import functools
+
+from .utils import (
+    unpack_from_stream as _unpack_from_stream,
+    eof_aware_read as _eof_aware_read,
+    log_dict,
+)
 
 PALETTE_SEGMENT = 0x14
 PICTURE_SEGMENT = 0x15
-BUTTON_SEGMENT  = 0x18
+BUTTON_SEGMENT  = 0x18 # noqa
 DISPLAY_SEGMENT = 0x80
 
 log = logging.getLogger("parser")
-
-def _eof_aware_read(stream, length, fail_on_no_data=False):
-    ret = stream.read(length)
-    if not ret:
-        if fail_on_no_data:
-            raise EOFError()
-
-        return None
-
-    if len(ret) < length:
-        raise EOFError()
-
-    return ret
-
-
-def _unpack_from_stream(fmt, stream):
-    data = _eof_aware_read(stream, struct.calcsize(fmt))
-    if not data:
-        return None
-
-    return struct.unpack(fmt, data)
-
-
-def _dump_dict(d):
-    def _dump_value(v):
-        if isinstance(v, dict):
-            return "{{{}}}".format(_dump_dict(v))
-        elif isinstance(v, (bytes, list)):
-            return "<Len: {}>".format(len(v))
-
-        return str(v)
-
-    return ", ".join(["=".join([str(k), _dump_value(v)]) for k, v in d.items()])
-
-
-def _log_dict(d, prefix=""):
-    log.debug(prefix + _dump_dict(d))
+_log_dict = functools.partial(log_dict, log)
 
 
 def igs_raw_segments(stream):
@@ -132,25 +103,30 @@ def parse_picture_segment(stream):
 
 
 def parse_button_segment(stream):
-    # [u16 width] [u16 height] [u8 framerate_id] [u16 unkwown] [u8 flags]
-    # [u32 in_time] [u32 to]
-    width, height, framerate_id, _, flags, in_time, to = \
-        _unpack_from_stream(">HHBHBII", stream)
+    # Reference: http://git.videolan.org/?p=libbluray.git;a=tree;f=src/libbluray/decoders # noqa
+    # [u16 width] [u16 height] [u8 framerate_id] [u16 composition_number]
+    # [u8 composition_state] [u8 seq_descriptor] [u24 data_len] [u8 model_flags] # noqa
+    (width, height, framerate_id, composition_number, composition_state,
+        seq_descriptor, _, _, _, model_flags) = \
+        _unpack_from_stream(">HHBHBBBBBB", stream)
 
-    if to == 0:
-        # Ten more byte skipped (output generated by TMpegEnc Authoring 5)
-        _eof_aware_read(stream, 10)
-
-    page_count = ord(stream.read(1))
     ret = {
         "width": width,
         "height": height,
         "framerate_id": framerate_id,
-        "flags": flags,
-        "in_time": in_time,
-        "to": to,
+        "composition_number": composition_number,
+        "composition_state": composition_state,
+        "seq_descriptor": seq_descriptor,
+        "model_flags": model_flags,
         "pages": [],
     }
+    if (model_flags & 0x80) == 0:
+        ret["composition_timeout_pts"] = _eof_aware_read(stream, 5, True)
+        ret["selection_timeout_pts"] = _eof_aware_read(stream, 5, True)
+
+    ret["user_timeout_duration"] = _eof_aware_read(stream, 3, True)
+
+    page_count = ord(stream.read(1))
     _log_dict(ret, "Button segment, ")
     for i in range(page_count):
         # [u8 page_id] [u8 ?] [u64 uo]

igstools/utils.py

@@ -0,0 +1,43 @@
+import struct
+
+
+def eof_aware_read(stream, length, fail_on_no_data=False):
+    if length == 0:
+        return b""
+
+    ret = stream.read(length)
+    if not ret:
+        if fail_on_no_data:
+            raise EOFError()
+
+        return None
+
+    if len(ret) < length:
+        raise EOFError()
+
+    return ret
+
+
+def unpack_from_stream(fmt, stream):
+    data = eof_aware_read(stream, struct.calcsize(fmt))
+    if not data:
+        return None
+
+    return struct.unpack(fmt, data)
+
+
+def dump_dict(d):
+    def _dump_value(v):
+        if isinstance(v, dict):
+            return "{{{}}}".format(dump_dict(v))
+        elif isinstance(v, (bytes, list)):
+            return "<Len: {}>".format(len(v))
+
+        return str(v)
+
+    return ", ".join(["=".join([str(k), _dump_value(v)])
+                      for k, v in d.items()])
+
+
+def log_dict(log, d, prefix=""):
+    log.debug(prefix + dump_dict(d))