On 12/22/2011 01:38 AM, Ronald S. Bultje wrote: > Hi, > > On Wed, Dec 21, 2011 at 10:36 PM, Ronald S. Bultje <[email protected] > <mailto:[email protected]>> wrote: > > > > On Wed, Dec 21, 2011 at 7:32 PM, Justin Ruggles > <[email protected] <mailto:[email protected]>> wrote: > > --- > libavcodec/bytestream.h | 31 ++++++++++++++++++++++++++++++- > 1 files changed, 30 insertions(+), 1 deletions(-) > > > Will you use this for something? If so, patch OK. If not, I wonder > whether we should add it...
For example, I was working on fixing the overreads in the VQA video decoder. It reads through the packet to get chunk offsets and sizes, then parses them in a specific order. Having tell and seek would mean we don't have to manually track the position separately in order to save the offsets, and we could seek instead of reinit/skip. > > I also just noticed a potential bug in our bytestream2 functions: > > if (g->buffer_end - g->buffer < bytes) > return 0; > > This will not return 0 on overreads, but rather repeat the last byte. > I'm not sure that's right. I believe peek and read should always read > the location, but only adjust the offset if we're not yet beyond it. > This is how bitstream works also. Maybe I'm missing something, but it seems like this is the way it works currently. If buffer == buffer_end then we're already past the last valid byte. The only potential odd situation would be, for example, if we try to read 4 bytes when there are only 3 bytes left it will return 0 and not increment, and then reading 1 or 2 bytes will still return valid data. -Justin _______________________________________________ libav-devel mailing list [email protected] https://lists.libav.org/mailman/listinfo/libav-devel
