diff --git a/scripts/cut_bs.py b/scripts/cut_bs.py
index 37f19733df609436176b22f16c6eb348370430ec..e54e99fdfecbbd694a23791b61f9652b78024f50 100755
--- a/scripts/cut_bs.py
+++ b/scripts/cut_bs.py
@@ -39,75 +39,63 @@ SID_BITS = {35, 48, 104}
 SYNC_WORDS = {b"!k", b" k"}
 
 
-def cut_to_length(fp, fp_out, length):
-    assert length > 0
-
+def get_next_frame(fp):
+    eof = False
+    n_bits = 0
+    data = None
+    sync_word = fp.read(2)
+    if sync_word == b"":
+        eof = True
+        return (sync_word, n_bits, data, eof)
+    if sync_word not in SYNC_WORDS:
+        raise ValueError("Bad Sync word!")
+    n_bits = struct.unpack("h", fp.read(2))[0]
+    data = fp.read(n_bits * 2)
+    return (sync_word, n_bits, data, eof)
+
+
+def write_frame(fp_out, sync_word, n_bits, data):
+    fp_out.write(sync_word)
+    fp_out.write(struct.pack("h", n_bits))
+    fp_out.write(data)
+
+
+def cut_from_start(fp, fp_out, start_frame=0, length=-1, start_with_sid=False):
     fr_cnt = 0
-
-    for f in range(length):
-        sync_word = fp.read(2)
-        if sync_word == b"":
-            return fr_cnt
-        if sync_word not in SYNC_WORDS:
-            raise ValueError("Bad Sync word!")
-        n_bits_bs = fp.read(2)
-        n_bits = struct.unpack("h", n_bits_bs)[0]
-        fp_out.write(sync_word)
-        fp_out.write(n_bits_bs)
-        fp_out.write(fp.read(n_bits * 2))
-        fr_cnt += 1
-
-    return fr_cnt
-
-
-def cut_from_start(fp, fp_out, start_frame=0, start_with_sid=False):
+    extracted_frames_cnt = 0
+    eof = False
     # cut until start frame
-    fr_cnt = 0
-    cut_cnt = 0
-    for cur_frame in range(start_frame):
-        sync_word = fp.read(2)
-        if sync_word == b"":
-            return (fr_cnt, cut_cnt)
-        if sync_word not in SYNC_WORDS:
-            raise ValueError("Bad Sync word!")
-        n_bits = struct.unpack("h", fp.read(2))[0]
-        fp.read(n_bits * 2)
-        fr_cnt += 1
-        cut_cnt += 1
+    while fr_cnt < start_frame and not eof:
+        (sync_word, n_bits, data, eof) = get_next_frame(fp)
+        if not eof:
+            fr_cnt += 1
+    # cut until SID frame
     if start_with_sid:
         found = False
-        while not found:
-            sync_word = fp.read(2)
-            if sync_word == b"":
-                return (fr_cnt, cut_cnt)
-            if sync_word not in SYNC_WORDS:
-                raise ValueError("Bad Sync word!")
-            n_bits_bs = fp.read(2)
-            n_bits = struct.unpack("h", n_bits_bs)[0]
-            if n_bits in SID_BITS:
-                found = True
-                fp_out.write(sync_word)
-                fp_out.write(n_bits_bs)
-                fp_out.write(fp.read(n_bits * 2))
-            else:
-                fp.read(n_bits * 2)
-                cut_cnt += 1
+        while not found and not eof:
+            (sync_word, n_bits, data, eof) = get_next_frame(fp)
+            if not eof:
+                if n_bits in SID_BITS:
+                    found = True
+                    fp.seek(-(4 + n_bits * 2), 1)  # Found SID, rewind
+                else:
+                    fr_cnt += 1
+    # transfer frames
+    while length != 0 and not eof:
+        (sync_word, n_bits, data, eof) = get_next_frame(fp)
+        if not eof:
+            write_frame(fp_out, sync_word, n_bits, data)
+            fr_cnt += 1
+            extracted_frames_cnt += 1
+            length -= 1
+
+    # count remaining frames, if any
+    while not eof:
+        (sync_word, n_bits, data, eof) = get_next_frame(fp)
+        if not eof:
             fr_cnt += 1
 
-    # transfer remaining frames
-    while True:
-        sync_word = fp.read(2)
-        if sync_word == b"":
-            break
-        if sync_word not in SYNC_WORDS:
-            raise ValueError("Bad Sync word!")
-        n_bits_bs = fp.read(2)
-        n_bits = struct.unpack("h", n_bits_bs)[0]
-        fp_out.write(sync_word)
-        fp_out.write(n_bits_bs)
-        fp_out.write(fp.read(n_bits * 2))
-        fr_cnt += 1
-    return (fr_cnt, cut_cnt)
+    return (fr_cnt, extracted_frames_cnt)
 
 
 if __name__ == "__main__":
@@ -138,24 +126,25 @@ if __name__ == "__main__":
     if not os.path.exists(os.path.realpath(my_args.bs_in)):
         print(f"\nInput file {my_args.bs_in} does not exist!")
         sys.exit(-1)
-    if not os.path.exists(os.path.realpath(my_args.bs_out)):
-        print(f"\nOutput file {my_args.bs_out} does not exist, creating it!")
-    else:
-        print(f"\nOutput file {my_args.bs_out} does exist, overwriting it!")
+    if os.path.exists(os.path.realpath(my_args.bs_out)):
+        print(f"\nOutput file {my_args.bs_out} exists, overwriting it!")
 
     with open(my_args.bs_in, "rb") as fp_in:
         with open(my_args.bs_out, "wb") as fp_out:
-            if my_args.sid or my_args.frame:
-                fr_cnt, cut_cnt = cut_from_start(
-                    fp_in, fp_out, start_frame=my_args.frame, start_with_sid=my_args.sid
+            fr_cnt, extracted_frames_cnt = cut_from_start(
+                fp_in,
+                fp_out,
+                start_frame=my_args.frame,
+                length=my_args.length,
+                start_with_sid=my_args.sid,
+            )
+            if extracted_frames_cnt == 0:
+                print(f"\nExtracted 0 frames!")
+                sys.exit(-1)
+            if my_args.length != -1 and extracted_frames_cnt != my_args.length:
+                print(
+                    f"Warning! Requested {my_args.length}, only {extracted_frames_cnt} obtained!"
                 )
-                if my_args.sid and (fr_cnt == cut_cnt):
-                    print("Warning! No SID frame found in bitstream!")
-                print(f"Cut {cut_cnt} of {fr_cnt} frames from {my_args.bs_in}")
-            elif my_args.length:
-                fr_cnt = cut_to_length(fp_in, fp_out, my_args.length)
-                if fr_cnt != my_args.length:
-                    print(
-                        f"Warning! Could not cut to length {my_args.length} as bitstream only contained {fr_cnt} frames!"
-                    )
-                print(f"Cut {my_args.bs_in} to {fr_cnt} frames")
+            print(
+                f"Extracted {extracted_frames_cnt} out of {fr_cnt} frames from {my_args.bs_in}"
+            )