Print Error Message for Bad AVC Profile

[dukesook]

A common error for the avcC box is providing profile values despite AVCProfileIndication variable saying there shouldn't be.

This PR prints an additional message informing the user of the issue.

[rbouqueau]

I'm not sure this test belongs here. Parsing may fail e.g. with truncated boxes. I'm ok to stop parsing with some exception - and why not find a mecanism to display the message from the exception.

What do you think?

PS: typo: AVCProfileIndiciation should be AVCProfileIndication

[dukesook]

I originally changed

    } catch(...) {
      fprintf(stderr, "Failed to parse box: '%s'\n", toString(subReader.myBox.fourcc).c_str());
      exit(1);
    }

to

    } catch(const std::exception &e) {
      fprintf(stderr, "%s\n", e.what());
      fprintf(stderr, "Failed to parse box: '%s'\n", toString(subReader.myBox.fourcc).c_str());
      exit(1);
    }

But this changed the output for many .ref test files, so running check failed.

[rbouqueau]

Changing a lot of .ref files is not an issue. But I feel the rationale for this change is something else: an ISOBMFF box is truncated and CW keeps on processing without any warning. Is that correct?

If so, we could evaluate a bunch of options:

• Display error inside br->sym(); calls when there are not enough bits left in the bitstream (maybe injecting some context inside the bitstream reader to improve the error message?).
• Add option parsing errors fatal (but only once parsing is completed). I think CW should be liberal in what it accepts by default.

What do you think?

[dukesook]

an ISOBMFF box is truncated and CW keeps on processing without any warning

No, the bit reader immediately throws an error:

  if(AVCProfileIndication != 66 && AVCProfileIndication != 77 && AVCProfileIndication != 88) {
    br->sym("reserved9", 6); // Throws Error!

  ENSURE(byteOffset < size, "BitReader::bit() overflow");

The CW stops processing and prints:
Failed to parse box: accC

Sample File: bad-avcC.box