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iniw wants to merge 7 commits into from
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Improve the performance of dissolve transitions #1343

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5b1a030
luma: don't convert opaque frames to rgba for fix_background_alpha
iniw Oct 13, 2026
38299b2
luma: dissolve opaque yuv422 frames in slices
iniw Oct 13, 2026
951c582
avformat: convert yuv420p to yuyv422 without libswscale
iniw Oct 13, 2026
3be22b7
avformat: copy the probed stream information to the audio context
iniw Oct 13, 2026
cfc6cc2
avformat: copy the probed stream information to the seek-test context
iniw Oct 13, 2026
4ac17a0
framework: copy large images on several threads
iniw Oct 13, 2026
25a34c4
avformat: find the error concealment frame in the image cache
iniw Oct 13, 2026
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44 changes: 40 additions & 4 deletions src/framework/mlt_frame.c
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Original file line number Diff line number Diff line change
Expand Up @@ -26,6 +26,7 @@
#include "mlt_log.h"
#include "mlt_producer.h"
#include "mlt_profile.h"
#include "mlt_slices.h"

#include <stdio.h>
#include <stdlib.h>
Expand Down Expand Up @@ -1334,6 +1335,41 @@ mlt_properties mlt_frame_get_unique_properties(mlt_frame self, mlt_service servi
return mlt_properties_get_data(MLT_FRAME_PROPERTIES(self), unique, NULL);
}

struct copy_slice_context
{
uint8_t *dst;
const uint8_t *src;
int size;
};

static int copy_slice(int id, int index, int count, void *cookie)
{
struct copy_slice_context *ctx = cookie;
int start;
int size = mlt_slices_size_slice(count, index, ctx->size, &start);
memcpy(ctx->dst + start, ctx->src + start, size);
return 0;
}

/** The size from which copy_buffer() uses several threads. Images up to 1080p yuv422
* (about 4 MB) are copied with one memcpy() as before; 4K images and 1080p rgba
* images are copied in slices.
*/
#define SLICED_COPY_MIN_SIZE (4 << 20)

/** Copy a buffer, in slices on several threads when it is large, because one thread
* cannot use all of the memory bandwidth.
*/
static void copy_buffer(void *dst, const void *src, int size)

@ddennedy ddennedy Oct 27, 2026

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This calls mlt_slices_run_normal from a public framework function. If a slice job anywhere, including in third-party modules, clones a frame, the global pool can deadlock. "No slice job in MLT clones a frame" is not a guarantee, and the gain is about 1.3 ms per frame. It isn't worth the risk.

{
if (size < SLICED_COPY_MIN_SIZE) {
memcpy(dst, src, size);
return;
}
struct copy_slice_context ctx = {.dst = dst, .src = src, .size = size};
mlt_slices_run_normal(0, copy_slice, &ctx);
}

/** Make a copy of a frame.
*
* This does not copy the get_image/get_audio processing stacks or any
Expand Down Expand Up @@ -1387,7 +1423,7 @@ mlt_frame mlt_frame_clone(mlt_frame self, int is_deep)
if (!size)
size = mlt_image_format_size(format, width, height, NULL);
copy = mlt_pool_alloc(size);
memcpy(copy, data, size);
copy_buffer(copy, data, size);
mlt_properties_set_data(new_props, "image", copy, size, mlt_pool_release, NULL);

size = 0;
Expand All @@ -1396,7 +1432,7 @@ mlt_frame mlt_frame_clone(mlt_frame self, int is_deep)
if (!size)
size = width * height;
copy = mlt_pool_alloc(size);
memcpy(copy, data, size);
copy_buffer(copy, data, size);
mlt_properties_set_data(new_props, "alpha", copy, size, mlt_pool_release, NULL);
};
}
Expand Down Expand Up @@ -1527,7 +1563,7 @@ mlt_frame mlt_frame_clone_image(mlt_frame self, int is_deep)
if (!size)
size = mlt_image_format_size(format, width, height, NULL);
copy = mlt_pool_alloc(size);
memcpy(copy, data, size);
copy_buffer(copy, data, size);
mlt_properties_set_data(new_props, "image", copy, size, mlt_pool_release, NULL);

size = 0;
Expand All @@ -1536,7 +1572,7 @@ mlt_frame mlt_frame_clone_image(mlt_frame self, int is_deep)
if (!size)
size = width * height;
copy = mlt_pool_alloc(size);
memcpy(copy, data, size);
copy_buffer(copy, data, size);
mlt_properties_set_data(new_props, "alpha", copy, size, mlt_pool_release, NULL);
};
}
Expand Down
61 changes: 21 additions & 40 deletions src/modules/avformat/common.c
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Original file line number Diff line number Diff line change
Expand Up @@ -239,60 +239,41 @@ mlt_channel_layout mlt_get_channel_layout_or_default(const char *name, int chann
return layout;
}

const int *mlt_get_sws_coefficients(mlt_colorspace colorspace)
{
switch (colorspace) {
case mlt_colorspace_smpte170m:
case mlt_colorspace_bt470bg:
case mlt_colorspace_bt601:
return sws_getCoefficients(SWS_CS_ITU601);
case mlt_colorspace_smpte240m:
return sws_getCoefficients(SWS_CS_SMPTE240M);
case mlt_colorspace_bt709:
return sws_getCoefficients(SWS_CS_ITU709);
case mlt_colorspace_bt2020_ncl:
case mlt_colorspace_bt2020_cl:
return sws_getCoefficients(SWS_CS_BT2020);
default:
return sws_getCoefficients(SWS_CS_DEFAULT);
}
}

int mlt_set_luma_transfer(struct SwsContext *context,
mlt_colorspace src_colorspace,
mlt_colorspace dst_colorspace,
int src_full_range,
int dst_full_range)
{
const int *src_coefficients = sws_getCoefficients(SWS_CS_DEFAULT);
const int *dst_coefficients = sws_getCoefficients(SWS_CS_DEFAULT);
int brightness = 0;
int contrast = 1 << 16;
int saturation = 1 << 16;
int src_range = src_full_range ? 1 : 0;
int dst_range = dst_full_range ? 1 : 0;

switch (src_colorspace) {
case mlt_colorspace_smpte170m:
case mlt_colorspace_bt470bg:
case mlt_colorspace_bt601:
src_coefficients = sws_getCoefficients(SWS_CS_ITU601);
break;
case mlt_colorspace_smpte240m:
src_coefficients = sws_getCoefficients(SWS_CS_SMPTE240M);
break;
case mlt_colorspace_bt709:
src_coefficients = sws_getCoefficients(SWS_CS_ITU709);
break;
case mlt_colorspace_bt2020_ncl:
case mlt_colorspace_bt2020_cl:
src_coefficients = sws_getCoefficients(SWS_CS_BT2020);
default:
break;
}
switch (dst_colorspace) {
case mlt_colorspace_smpte170m:
case mlt_colorspace_bt470bg:
case mlt_colorspace_bt601:
dst_coefficients = sws_getCoefficients(SWS_CS_ITU601);
break;
case mlt_colorspace_smpte240m:
dst_coefficients = sws_getCoefficients(SWS_CS_SMPTE240M);
break;
case mlt_colorspace_bt709:
dst_coefficients = sws_getCoefficients(SWS_CS_ITU709);
break;
case mlt_colorspace_bt2020_ncl:
case mlt_colorspace_bt2020_cl:
dst_coefficients = sws_getCoefficients(SWS_CS_BT2020);
default:
break;
}
return sws_setColorspaceDetails(context,
src_coefficients,
mlt_get_sws_coefficients(src_colorspace),
src_range,
dst_coefficients,
mlt_get_sws_coefficients(dst_colorspace),
dst_range,
brightness,
contrast,
Expand Down
1 change: 1 addition & 0 deletions src/modules/avformat/common.h
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Original file line number Diff line number Diff line change
Expand Up @@ -36,6 +36,7 @@ mlt_channel_layout av_channel_layout_to_mlt(AVChannelLayout *layout);
mlt_channel_layout av_channel_layout_to_mlt(int64_t layout);
#endif
mlt_channel_layout mlt_get_channel_layout_or_default(const char *name, int channels);
const int *mlt_get_sws_coefficients(mlt_colorspace colorspace);
int mlt_set_luma_transfer(struct SwsContext *context,
mlt_colorspace src_colorspace,
mlt_colorspace dst_colorspace,
Expand Down
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