[FFmpeg-devel] [PATCH] rmdec.c: merge old/new packet reading code

[Ronald S. Bultje]

Hi Kostya,

so let's go to this one now, this is the last easy rmdec patch in my
queue (after this we get to multirate, let's do that separately).

On Wed, Mar 11, 2009 at 1:46 AM, Kostya <kostya.shishkov at gmail.com> wrote:
> Can we use some simpler solution - like when packet flags & 2 and there was
> no remaining_len before it (i.e. we are not inside partial packet)
> nor after it (i.e. we were not reading start of partial packet, but maybe
> this condition can be omitted) then add this packet to index.

remaining_len isn't particularly useful. An entire video can take up
one packet, part of a packet (beginning or end), or split over
multiple full or partial packets.

In fact, my current patch already screws up there since we're not
checking remaining_len appropriately. We should only write index
entries for the beginning of a RM packet, so remaining_len before
should be zero before the call to ff_rm_parse_packet().

So then, if remaining_len is zero (= start of RM packet), how do we
know that this packet contains the first slice of a video frame, or a
full video frame (this is dependent on the variablt "type", and slice
number is "seq"), or a full audio frame (codec-dependent, e.g. 14k4RA,
AC3, AAC) or the first "slice" of a series of scrambled audio packets
(28k8, ATRAC3, cook, QCELP, etc.)?

Any hints on how to easiest accomplish that is appreciated.

> Passing two additional arguments for getting data to index does not seem right.

I agree, hence my "poor-man's attempt". :-).

Ronald