This avoids mpegvideo.c having to deal with the fact that
the encoders use two sets of blocks and is in preparation
for not allocating blocks at all.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
Now that every slice (and therefore every thread) uses its own
DC array, one can simply set the out-of-slice DC values to its
expected values (this is not possible for the decoders due
to error resilience).
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
This fixes data races (which are UB) in the MPEG-4 and H.263+
encoder when predicting DC values; these encoders unconditionally
read values from the line above the current line and only check
lateron (via first_slice_line) whether said prediction can be used
at all. It will also allow to remove said checks (by setting the
entries to 1024 upon opening a new slice).
The vsynth{1,2,3,_lena}-mpeg4-thread FATE tests were affected by this:
https://fate.ffmpeg.org/report.cgi?slot=x86_64-archlinux-gcc-tsan-slices&time=20250613002615
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
The chroma dc_val pointers are mostly unused (accesses use
dc_val[0] and block_index), so remove them.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
They are currently allocated separately per slice; allocating them
jointly allows to avoid saving them in ff_update_duplicate_context().
The way it is done also avoids allocating ac_val for encoders that
don't need it (e.g. H.263 or H.263+ with AIC).
This entailed moving setting nb_slices to ff_mpv_init_context_frame()
which is called from ff_mpv_common_frame_size_change(). The resultant
nb_slices will always be one when called from a decoder using
ff_mpv_common_frame_size_change().
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
All callers check the corresponding entry of MpegEncContext.mbintra_table
and if set (indicating that the intra tables might have been written to
when decodeing a intra MB, so that they are "dirty"), call
ff_clean_intra_table_entries(), which resets them to default values
and resets the mbintra_table entry. Move resetting to the callers
(via an inline function that also performs the checks). This currently
has the advantage that the additional load of the mbintra_table ptr
can be avoided. It will also allow to simplify
ff_clean_intra_table_entries() (by using block_index[4] and [5]).
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
Allocate them before the slice contexts, so that they are automatically
copied to the slice contexts. This avoids having to set them in a loop.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
This will allow to perform initializations between ff_mpv_common_init()
and ff_mpv_init_duplicate_contexts() that will be automatically
copied to the slice contexts.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
This means that these buffers won't be allocated any more
for H.263+ with AIC disabled.
Also remove setting h263_plus for the RV20 encoder,
as it has only been done to force allocating dc_val.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
Multiple PutBitContexts are used when encoding partitioned
frames. When there are multiple candidates for macroblock types,
multiple states (namely the state before encoding the current MB,
the best state among the ones already tried and the current one)
need to be kept; duplicates of the PutBitContexts are among this
state. The temporary buffers for them are kept on the stack
in encode_thread() and their size is quite generous (MAX_MB_SIZE
- 3000 bytes). This commit uses tighter bounds, bringing the
size of the pb2 buffer down to 15 bytes.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
It is only used by the MPEG-4 decoder and the encoders.
Notice that this field is a per-frame property and therefore
does not need to by synced in mpeg4_update_thread_context().
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
They have a fixed size and given that nowadays
MotionEstContext is no longer in any decoder's private context,
it is not wasteful to just put it into there.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
encode_thread() puts two MPVEncContexts (2*6516B here)
on the stack and zeroes one of them in order to
temporarily store the variables that get changed
during encoding a macroblock (when there is more than
one candidate type for a macroblock). This is wasteful
and therefore this commit adds a small (328B here) structure
to store exactly the fields that actually need to be backed
up. Then one can extend MPVEncContext without fearing
too use up to much stack.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
Fixes a regression caused by my desire to use loop-scope
for iterators in 72bf3d3c12.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
For all encoders and all decoders except MPEG-4 the unquantize
functions to use don't change at all and therefore needn't be
kept in the context. So discard them after setting them;
for MPEG-4, the functions get assigned on a per-frame basis.
Decoders not using any unquantize functions (H.261, MPEG-1/2)
as well as decoders that only call ff_mpv_reconstruct_mb()
through error resilience (RV30/40, the VC-1 family) don't have
the remaining pointers set at all.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
Only set them after mb_x and mb_y are known which happens
only after the call to ff_h261_reorder_mb_index().
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
Reset them in ff_me_init_pic(). It is the appropriate place for it
and allows to remove resetting code from multiple places
(e.g. mpegvideo_enc.c resetted it in two different places
(one for the main slice context, one for all the others)).
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
Also avoid casts and parentheses.
(This is only possible now because ff_update_duplicate_context()
no longer touches the PutBitContext.)
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
This happens currently for the non-main slice contexts.
But these variables get reset at the start of encode_thread()
anyway for all slices, so this is unnecessary.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
Many of the fields of MpegEncContext (which is also used by decoders)
are actually only used by encoders. Therefore this commit adds
a new encoder-only structure and moves all of the encoder-only
fields to it except for those which require more explicit
synchronisation between the main slice context and the other
slice contexts. This synchronisation is currently mainly provided
by ff_update_thread_context() which simply copies most of
the main slice context over the other slice contexts. Fields
which are moved to the new MPVEncContext no longer participate
in this (which is desired, because it is horrible and for the
fields b) below wasteful) which means that some fields can only
be moved when explicit synchronisation code is added in later commits.
More explicitly, this commit moves the following fields:
a) Fields not copied by ff_update_duplicate_context():
dct_error_sum and dct_count; the former does not need synchronisation,
the latter is synchronised in merge_context_after_encode().
b) Fields which do not change after initialisation (these fields
could also be put into MPVMainEncContext at the cost of
an indirection to access them): lambda_table, adaptive_quant,
{luma,chroma}_elim_threshold, new_pic, fdsp, mpvencdsp, pdsp,
{p,b_forw,b_back,b_bidir_forw,b_bidir_back,b_direct,b_field}_mv_table,
[pb]_field_select_table, mb_{type,var,mean}, mc_mb_var, {min,max}_qcoeff,
{inter,intra}_quant_bias, ac_esc_length, the *_vlc_length fields,
the q_{intra,inter,chroma_intra}_matrix{,16}, dct_offset, mb_info,
mjpeg_ctx, rtp_mode, rtp_payload_size, encode_mb, all function
pointers, mpv_flags, quantizer_noise_shaping,
frame_reconstruction_bitfield, error_rate and intra_penalty.
c) Fields which are already (re)set explicitly: The PutBitContexts
pb, tex_pb, pb2; dquant, skipdct, encoding_error, the statistics
fields {mv,i_tex,p_tex,misc,last}_bits and i_count; last_mv_dir,
esc_pos (reset when writing the header).
d) Fields which are only used by encoders not supporting slice
threading for which synchronisation doesn't matter: esc3_level_length
and the remaining mb_info fields.
e) coded_score: This field is only really used when FF_MPV_FLAG_CBP_RD
is set (which implies trellis) and even then it is only used for
non-intra blocks. For these blocks dct_quantize_trellis_c() either
sets coded_score[n] or returns a last_non_zero value of -1
in which case coded_score will be reset in encode_mb_internal().
Therefore no old values are ever used.
The MotionEstContext has not been moved yet.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
Namely after the main slice context has already been initialized,
so that this initialized state is directly copied to the newly
created slice contexts without relying on it being copied
by ff_update_duplicate_context(). This is in preparation for further
commits.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
last_pict_type, last_non_b_pict_type and last_lambda_for
are only used by the encoder's main thread.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
(Checking in the same way for intra_only is not straightforward,
because at least p_mv_table is written to even in intra_only
mode.)
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
Also allocate them jointly (thereby reducing the number of base
arrays considerably) and already set them on all slice contexts;
don't rely on ff_update_duplicate_context().
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
dct_error_sum and me.map are allocated per slice-context
and therefore their allocation has not been moved to
mpegvideoenc.c in 0154fb43e3.
This commit changes this by allocating them jointly and
moving said allocations to mpegvideo_enc.c like the other
encoder-only buffers.
The buffers are suitably aligned to ensure that no false
sharing occurs.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
