This implements the 0x10 frame format for Interplay MVE movies. The
format is a variation on the 0x06 format with some changes. In addition
to the decoding map there's also a skip map. This skip map is used to
determine what 8x8 blocks can change in a particular frame.
This format expects to be able to copy an 8x8 block from before the last
time it was changed. This can be an arbitrary time in the past. In order
to implement this this decoder allocates two additional AVFrames where
actual decoding happens. At the end of a frame decoding changed blocks
are copied to a finished frame based on the skip map.
The skip map's encoding is a little convulted, I'll refer to the code
for details.
Values in the decoding map are the same as in format 0x06.
Signed-off-by: Hein-Pieter van Braam <hp@tmm.cx>
This implements the 0x06 frame format for Interplay MVE movies. The
format is relatively simple. The video data consists of two parts:
16 bits per 8x8 block movement data
a number of 8x8 blocks of pixel data
For each 8x8 block of pixel data the movement data is consulted. There
are 3 possible meanings of the movement data:
* zero : copy the 8x8 block from the pixel data
* negative : copy the 8x8 block from the previous frame from an offset
determined by the actual value of the entry -0xC000.
* positive : copy the 8x8 block from the current frame from an offset
determined by the actual value of the entry -0x4000
Decoding happens in two passes, in the fist pass only new pixeldata is
copied, during the second pass data is copied from the previous and
current frames.
The codec expects that the current frame being decoded to still has the
data from 2 frames ago on it when decoding starts.
Signed-off-by: Hein-Pieter van Braam <hp@tmm.cx>
Interplay MVE can contain up to three different frame formats. They
require different streams of information to render a frame. This patch
changes the IP packet format to prepare for the extra frame formats.
Signed-off-by: Hein-Pieter van Braam <hp@tmm.cx>
Interplay MVE movies have a SEND_BUFFER operation. Only after this
command does the current decoding buffer get displayed. This is required
for the other frame formats. They are fixed-size and can't always encode
a full frame worth of pixeldata.
This code prevents half-finished frames from being emitted.
Signed-off-by: Hein-Pieter van Braam <hp@tmm.cx>
Currently, AVStream contains an embedded AVCodecContext instance, which
is used by demuxers to export stream parameters to the caller and by
muxers to receive stream parameters from the caller. It is also used
internally as the codec context that is passed to parsers.
In addition, it is also widely used by the callers as the decoding (when
demuxer) or encoding (when muxing) context, though this has been
officially discouraged since Libav 11.
There are multiple important problems with this approach:
- the fields in AVCodecContext are in general one of
* stream parameters
* codec options
* codec state
However, it's not clear which ones are which. It is consequently
unclear which fields are a demuxer allowed to set or a muxer allowed to
read. This leads to erratic behaviour depending on whether decoding or
encoding is being performed or not (and whether it uses the AVStream
embedded codec context).
- various synchronization issues arising from the fact that the same
context is used by several different APIs (muxers/demuxers,
parsers, bitstream filters and encoders/decoders) simultaneously, with
there being no clear rules for who can modify what and the different
processes being typically delayed with respect to each other.
- avformat_find_stream_info() making it necessary to support opening
and closing a single codec context multiple times, thus
complicating the semantics of freeing various allocated objects in the
codec context.
Those problems are resolved by replacing the AVStream embedded codec
context with a newly added AVCodecParameters instance, which stores only
the stream parameters exported by the demuxers or read by the muxers.
The size of decoding map can differ from one calculated
internally, producing artifacts while decoding video.
Signed-off-by: Paul B Mahol <onemda@gmail.com>
Fixes use of uninitialized memory
Fixes: msan_uninit-mem_7fec1f40656c_4819_descent3_level5_16bit_partial.mve
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
Fixes use of uninitialized memory
Fixes: msan_uninit-mem_7f75b03c1f19_4820_descent3_level5_16bit_partial.mve
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
Fixes use of uninitialized memory
Fixes: msan_uninit-mem_7f81e836ef8c_5930_ipmovie_interplayvideo_interplay_dpcm__bislogo.mve
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
Fixes use of uninitialized data
Fixes: signal_sigsegv_1571228_5930_ipmovie_interplayvideo_interplay_dpcm__bislogo.mve
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
In the name of consistency:
get_byte -> avio_r8
get_<type> -> avio_r<type>
get_buffer -> avio_read
get_partial_buffer will be made private later
get_strz is left out becase I want to change it later to return
something useful.
Signed-off-by: Ronald S. Bultje <rsbultje@gmail.com>
(cherry picked from commit b7effd4e83)
Carl Eugen Hoyos
Hein-Pieter van Braam
Diego Biurrun
Vittorio Giovara
Anton Khirnov
Paul B Mahol
Luca Barbato
Michael Niedermayer
James Almer
Michael Niedermayer
Justin Ruggles
Janne Grunau
Carl Eugen Hoyos
Kostya Shishkov
Mans Rullgard