| Message ID | 20260720115144.4392-2-david.plowman@raspberrypi.com |
|---|---|
| State | New |
| Headers | show |
| Series |
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| Related | show |
Hi 2026. 07. 20. 13:10 keltezéssel, David Plowman írta: > Existing code was preferring fixed size outputs over ones with ranges, > resulting in raw output formats being preferred even when applications > ("cheese" is one such example) aren't expecting them and subsequently > fail. > > The revised version still prefers fixed size outputs over ones with > ranges, but will prefer non-raw (meaning non-Bayer) formats where > these are available. This still allows applications that explicitly > request raw formats to get them, but other applications will normally > get non-raw formats which they handle better. > > Fixes, for example, "cheese" on Raspberry Pi. > > Signed-off-by: David Plowman <david.plowman@raspberrypi.com> > --- > src/gstreamer/gstlibcamera-utils.cpp | 125 ++++++++++++++++++++------- > src/gstreamer/gstlibcamera-utils.h | 2 +- > src/gstreamer/gstlibcamerasrc.cpp | 3 +- > 3 files changed, 97 insertions(+), 33 deletions(-) > > diff --git a/src/gstreamer/gstlibcamera-utils.cpp b/src/gstreamer/gstlibcamera-utils.cpp > index 6541d478c..f0f128880 100644 > --- a/src/gstreamer/gstlibcamera-utils.cpp > +++ b/src/gstreamer/gstlibcamera-utils.cpp > @@ -9,6 +9,7 @@ > #include "gstlibcamera-utils.h" > > #include <string> > +#include <vector> > > #include <libcamera/control_ids.h> > #include <libcamera/formats.h> > @@ -435,61 +436,121 @@ gst_libcamera_stream_configuration_to_caps(const StreamConfiguration &stream_cfg > return caps; > } > > -void gst_libcamera_configure_stream_from_caps(StreamConfiguration &stream_cfg, > +/* > + * We will want to distinguish between caps structures corresponding to > + * raw and non-raw (processed) output images, as this will help inform > + * our choice of preferred format. > + * > + * We identify Bayer as being the principle "raw" format here, but note > + * that we are considering greyscale (images with one component) to be > + * raw too (e.g. a raw monochrome sensor). > + */ > +static bool > +gst_libcamera_structure_is_raw_capture(const GstStructure *s) > +{ > + if (gst_structure_has_name(s, "video/x-bayer")) > + return true; > + > + if (gst_structure_has_name(s, "video/x-raw")) { > + const gchar *format = gst_structure_get_string(s, "format"); > + if (!format) > + return false; > + > + const GstVideoFormatInfo *finfo = > + gst_video_format_get_info(gst_video_format_from_string(format)); > + > + return finfo->n_components == 1; > + } > + > + return false; > +} > + > +/* > + * Data recorded for each caps structure candidate, used to rank them > + * against each other in gst_libcamera_compare_caps_candidates(). > + */ > +struct CapsCandidate { > + guint index; > + bool is_raw; > + bool is_fixed; > + guint delta; > +}; > + > +static gint > +gst_libcamera_compare_caps_candidates(gconstpointer a, gconstpointer b) > +{ > + const CapsCandidate *ca = static_cast<const CapsCandidate *>(a); > + const CapsCandidate *cb = static_cast<const CapsCandidate *>(b); > + > + /* > + * Raw formats are likely to be useful only to applications that > + * specifically ask for them. Other applications will typically be > + * unable to handle them and fail, so prefer non-raw candidates. > + */ > + if (ca->is_raw != cb->is_raw) > + return ca->is_raw ? 1 : -1; > + > + /* Prefer a reliable fixed value over a range. */ > + if (ca->is_fixed != cb->is_fixed) > + return ca->is_fixed ? -1 : 1; > + > + /* Otherwise the closest size match wins. */ > + if (ca->delta != cb->delta) > + return ca->delta < cb->delta ? -1 : 1; > + > + return 0; > +} > + > +bool gst_libcamera_configure_stream_from_caps(StreamConfiguration &stream_cfg, > GstCaps *caps, GstVideoTransferFunction *transfer) > { > GstVideoFormat gst_format = pixel_format_to_gst_format(stream_cfg.pixelFormat); > guint i; > - gint best_fixed = -1, best_in_range = -1; > GstStructure *s; > > - /* > - * These are delta weight computed from: > - * ABS(width - stream_cfg.size.width) * ABS(height - stream_cfg.size.height) > - */ > - guint best_fixed_delta = G_MAXUINT; > - guint best_in_range_delta = G_MAXUINT; > - > /* First fixate the caps using default configuration value. */ > g_assert(gst_caps_is_writable(caps)); > > - /* Lookup the structure for a close match to the stream_cfg.size */ > + /* > + * Build a candidate for every available caps structure, and insert > + * it into a list kept sorted by preference as we go. The vector > + * is constructed at its final size immediately, so it's safe to use > + * pointers to the elements in it. > + */ > + std::vector<CapsCandidate> candidates(gst_caps_get_size(caps)); > + GList *sorted = nullptr; It looks to me that `sorted` is unnecessary. In fact, it looks to me that `candidates` is unnecessary as well. Now that there is a comparison function, it should be a matter of a minimum search, no? Meaning that you only need to store the current best? Or am I missing something? For example, like this: diff --git a/src/gstreamer/gstlibcamera-utils.cpp b/src/gstreamer/gstlibcamera-utils.cpp index f0f128880f..95be8a8dcb 100644 --- a/src/gstreamer/gstlibcamera-utils.cpp +++ b/src/gstreamer/gstlibcamera-utils.cpp @@ -8,8 +8,9 @@ #include "gstlibcamera-utils.h" +#include <cmath> +#include <optional> #include <string> -#include <vector> #include <libcamera/control_ids.h> #include <libcamera/formats.h> @@ -474,32 +475,28 @@ struct CapsCandidate { bool is_raw; bool is_fixed; guint delta; -}; - -static gint -gst_libcamera_compare_caps_candidates(gconstpointer a, gconstpointer b) -{ - const CapsCandidate *ca = static_cast<const CapsCandidate *>(a); - const CapsCandidate *cb = static_cast<const CapsCandidate *>(b); - /* - * Raw formats are likely to be useful only to applications that - * specifically ask for them. Other applications will typically be - * unable to handle them and fail, so prefer non-raw candidates. - */ - if (ca->is_raw != cb->is_raw) - return ca->is_raw ? 1 : -1; + constexpr bool operator<(const CapsCandidate &other) const + { + /* + * Raw formats are likely to be useful only to applications that + * specifically ask for them. Other applications will typically be + * unable to handle them and fail, so prefer non-raw candidates. + */ + if (is_raw != other.is_raw) + return !is_raw; - /* Prefer a reliable fixed value over a range. */ - if (ca->is_fixed != cb->is_fixed) - return ca->is_fixed ? -1 : 1; + /* Prefer a reliable fixed value over a range. */ + if (is_fixed != other.is_fixed) + return is_fixed; - /* Otherwise the closest size match wins. */ - if (ca->delta != cb->delta) - return ca->delta < cb->delta ? -1 : 1; + /* Otherwise the closest size match wins. */ + if (delta < other.delta) + return true; - return 0; -} + return false; + } +}; bool gst_libcamera_configure_stream_from_caps(StreamConfiguration &stream_cfg, GstCaps *caps, GstVideoTransferFunction *transfer) @@ -517,8 +514,7 @@ bool gst_libcamera_configure_stream_from_caps(StreamConfiguration &stream_cfg, * is constructed at its final size immediately, so it's safe to use * pointers to the elements in it. */ - std::vector<CapsCandidate> candidates(gst_caps_get_size(caps)); - GList *sorted = nullptr; + std::optional<CapsCandidate> best; for (i = 0; i < gst_caps_get_size(caps); i++) { s = gst_caps_get_structure(caps, i); @@ -536,21 +532,27 @@ bool gst_libcamera_configure_stream_from_caps(StreamConfiguration &stream_cfg, gst_structure_get_int(s, "height", &height); } - guint delta = ABS(width - (gint)stream_cfg.size.width) * ABS(height - (gint)stream_cfg.size.height); + guint delta = + guint(std::abs(width - (gint)stream_cfg.size.width)) + * guint(std::abs(height - (gint)stream_cfg.size.height)); + + CapsCandidate candidate = { + .index = i, + .is_raw = gst_libcamera_structure_is_raw_capture(s), + .is_fixed = is_fixed, + .delta = delta, + }; - candidates[i] = { i, gst_libcamera_structure_is_raw_capture(s), is_fixed, delta }; - sorted = g_list_insert_sorted(sorted, &candidates[i], gst_libcamera_compare_caps_candidates); + if (!best || candidate < *best) + best = candidate; } - if (!sorted) { + if (!best) { GST_WARNING("Failed to find a suitable caps structure to configure the stream"); return false; } - guint best = static_cast<CapsCandidate *>(sorted->data)->index; - g_list_free(sorted); - - s = gst_caps_get_structure(caps, best); + s = gst_caps_get_structure(caps, best->index); if (gst_structure_has_name(s, "video/x-raw")) { const gchar *format = gst_video_format_to_string(gst_format); > + > for (i = 0; i < gst_caps_get_size(caps); i++) { > s = gst_caps_get_structure(caps, i); > gint width, height; > - guint delta; > + bool is_fixed = gst_structure_has_field_typed(s, "width", G_TYPE_INT) && > + gst_structure_has_field_typed(s, "height", G_TYPE_INT); > > - if (gst_structure_has_field_typed(s, "width", G_TYPE_INT) && > - gst_structure_has_field_typed(s, "height", G_TYPE_INT)) { > + if (is_fixed) { > gst_structure_get_int(s, "width", &width); > gst_structure_get_int(s, "height", &height); > - > - delta = ABS(width - (gint)stream_cfg.size.width) * ABS(height - (gint)stream_cfg.size.height); > - > - if (delta < best_fixed_delta) { > - best_fixed_delta = delta; > - best_fixed = i; > - } > } else { > gst_structure_fixate_field_nearest_int(s, "width", stream_cfg.size.width); > gst_structure_fixate_field_nearest_int(s, "height", stream_cfg.size.height); > gst_structure_get_int(s, "width", &width); > gst_structure_get_int(s, "height", &height); > + } > > - delta = ABS(width - (gint)stream_cfg.size.width) * ABS(height - (gint)stream_cfg.size.height); > + guint delta = ABS(width - (gint)stream_cfg.size.width) * ABS(height - (gint)stream_cfg.size.height); > > - if (delta < best_in_range_delta) { > - best_in_range_delta = delta; > - best_in_range = i; > - } > - } > + candidates[i] = { i, gst_libcamera_structure_is_raw_capture(s), is_fixed, delta }; > + sorted = g_list_insert_sorted(sorted, &candidates[i], gst_libcamera_compare_caps_candidates); > + } > + > + if (!sorted) { > + GST_WARNING("Failed to find a suitable caps structure to configure the stream"); > + return false; > } > > - /* Prefer reliable fixed value over ranges */ > - if (best_fixed >= 0) > - s = gst_caps_get_structure(caps, best_fixed); > - else > - s = gst_caps_get_structure(caps, best_in_range); > + guint best = static_cast<CapsCandidate *>(sorted->data)->index; > + g_list_free(sorted); > + > + s = gst_caps_get_structure(caps, best); > > if (gst_structure_has_name(s, "video/x-raw")) { > const gchar *format = gst_video_format_to_string(gst_format); > @@ -529,6 +590,8 @@ void gst_libcamera_configure_stream_from_caps(StreamConfiguration &stream_cfg, > > stream_cfg.colorSpace = colorspace_from_colorimetry(colorimetry, transfer); > } > + > + return true; > } > > void gst_libcamera_get_framerate_from_caps(GstCaps *caps, > diff --git a/src/gstreamer/gstlibcamera-utils.h b/src/gstreamer/gstlibcamera-utils.h > index 35df56fb9..5ce0e839c 100644 > --- a/src/gstreamer/gstlibcamera-utils.h > +++ b/src/gstreamer/gstlibcamera-utils.h > @@ -18,7 +18,7 @@ > GstCaps *gst_libcamera_stream_formats_to_caps(const libcamera::StreamFormats &formats); > GstCaps *gst_libcamera_stream_configuration_to_caps(const libcamera::StreamConfiguration &stream_cfg, > GstVideoTransferFunction transfer); > -void gst_libcamera_configure_stream_from_caps(libcamera::StreamConfiguration &stream_cfg, > +bool gst_libcamera_configure_stream_from_caps(libcamera::StreamConfiguration &stream_cfg, > GstCaps *caps, GstVideoTransferFunction *transfer); > void gst_libcamera_get_framerate_from_caps(GstCaps *caps, GstStructure *element_caps); > void gst_libcamera_clamp_and_set_frameduration(libcamera::ControlList &controls, > diff --git a/src/gstreamer/gstlibcamerasrc.cpp b/src/gstreamer/gstlibcamerasrc.cpp > index 9061f9163..66b31ce82 100644 > --- a/src/gstreamer/gstlibcamerasrc.cpp > +++ b/src/gstreamer/gstlibcamerasrc.cpp > @@ -605,7 +605,8 @@ gst_libcamera_src_negotiate(GstLibcameraSrc *self) > > /* Fixate caps and configure the stream. */ > caps = gst_caps_make_writable(caps); > - gst_libcamera_configure_stream_from_caps(stream_cfg, caps, &transfer[i]); > + if (!gst_libcamera_configure_stream_from_caps(stream_cfg, caps, &transfer[i])) > + return false; > gst_libcamera_get_framerate_from_caps(caps, element_caps); > } >
diff --git a/src/gstreamer/gstlibcamera-utils.cpp b/src/gstreamer/gstlibcamera-utils.cpp index 6541d478c..f0f128880 100644 --- a/src/gstreamer/gstlibcamera-utils.cpp +++ b/src/gstreamer/gstlibcamera-utils.cpp @@ -9,6 +9,7 @@ #include "gstlibcamera-utils.h" #include <string> +#include <vector> #include <libcamera/control_ids.h> #include <libcamera/formats.h> @@ -435,61 +436,121 @@ gst_libcamera_stream_configuration_to_caps(const StreamConfiguration &stream_cfg return caps; } -void gst_libcamera_configure_stream_from_caps(StreamConfiguration &stream_cfg, +/* + * We will want to distinguish between caps structures corresponding to + * raw and non-raw (processed) output images, as this will help inform + * our choice of preferred format. + * + * We identify Bayer as being the principle "raw" format here, but note + * that we are considering greyscale (images with one component) to be + * raw too (e.g. a raw monochrome sensor). + */ +static bool +gst_libcamera_structure_is_raw_capture(const GstStructure *s) +{ + if (gst_structure_has_name(s, "video/x-bayer")) + return true; + + if (gst_structure_has_name(s, "video/x-raw")) { + const gchar *format = gst_structure_get_string(s, "format"); + if (!format) + return false; + + const GstVideoFormatInfo *finfo = + gst_video_format_get_info(gst_video_format_from_string(format)); + + return finfo->n_components == 1; + } + + return false; +} + +/* + * Data recorded for each caps structure candidate, used to rank them + * against each other in gst_libcamera_compare_caps_candidates(). + */ +struct CapsCandidate { + guint index; + bool is_raw; + bool is_fixed; + guint delta; +}; + +static gint +gst_libcamera_compare_caps_candidates(gconstpointer a, gconstpointer b) +{ + const CapsCandidate *ca = static_cast<const CapsCandidate *>(a); + const CapsCandidate *cb = static_cast<const CapsCandidate *>(b); + + /* + * Raw formats are likely to be useful only to applications that + * specifically ask for them. Other applications will typically be + * unable to handle them and fail, so prefer non-raw candidates. + */ + if (ca->is_raw != cb->is_raw) + return ca->is_raw ? 1 : -1; + + /* Prefer a reliable fixed value over a range. */ + if (ca->is_fixed != cb->is_fixed) + return ca->is_fixed ? -1 : 1; + + /* Otherwise the closest size match wins. */ + if (ca->delta != cb->delta) + return ca->delta < cb->delta ? -1 : 1; + + return 0; +} + +bool gst_libcamera_configure_stream_from_caps(StreamConfiguration &stream_cfg, GstCaps *caps, GstVideoTransferFunction *transfer) { GstVideoFormat gst_format = pixel_format_to_gst_format(stream_cfg.pixelFormat); guint i; - gint best_fixed = -1, best_in_range = -1; GstStructure *s; - /* - * These are delta weight computed from: - * ABS(width - stream_cfg.size.width) * ABS(height - stream_cfg.size.height) - */ - guint best_fixed_delta = G_MAXUINT; - guint best_in_range_delta = G_MAXUINT; - /* First fixate the caps using default configuration value. */ g_assert(gst_caps_is_writable(caps)); - /* Lookup the structure for a close match to the stream_cfg.size */ + /* + * Build a candidate for every available caps structure, and insert + * it into a list kept sorted by preference as we go. The vector + * is constructed at its final size immediately, so it's safe to use + * pointers to the elements in it. + */ + std::vector<CapsCandidate> candidates(gst_caps_get_size(caps)); + GList *sorted = nullptr; + for (i = 0; i < gst_caps_get_size(caps); i++) { s = gst_caps_get_structure(caps, i); gint width, height; - guint delta; + bool is_fixed = gst_structure_has_field_typed(s, "width", G_TYPE_INT) && + gst_structure_has_field_typed(s, "height", G_TYPE_INT); - if (gst_structure_has_field_typed(s, "width", G_TYPE_INT) && - gst_structure_has_field_typed(s, "height", G_TYPE_INT)) { + if (is_fixed) { gst_structure_get_int(s, "width", &width); gst_structure_get_int(s, "height", &height); - - delta = ABS(width - (gint)stream_cfg.size.width) * ABS(height - (gint)stream_cfg.size.height); - - if (delta < best_fixed_delta) { - best_fixed_delta = delta; - best_fixed = i; - } } else { gst_structure_fixate_field_nearest_int(s, "width", stream_cfg.size.width); gst_structure_fixate_field_nearest_int(s, "height", stream_cfg.size.height); gst_structure_get_int(s, "width", &width); gst_structure_get_int(s, "height", &height); + } - delta = ABS(width - (gint)stream_cfg.size.width) * ABS(height - (gint)stream_cfg.size.height); + guint delta = ABS(width - (gint)stream_cfg.size.width) * ABS(height - (gint)stream_cfg.size.height); - if (delta < best_in_range_delta) { - best_in_range_delta = delta; - best_in_range = i; - } - } + candidates[i] = { i, gst_libcamera_structure_is_raw_capture(s), is_fixed, delta }; + sorted = g_list_insert_sorted(sorted, &candidates[i], gst_libcamera_compare_caps_candidates); + } + + if (!sorted) { + GST_WARNING("Failed to find a suitable caps structure to configure the stream"); + return false; } - /* Prefer reliable fixed value over ranges */ - if (best_fixed >= 0) - s = gst_caps_get_structure(caps, best_fixed); - else - s = gst_caps_get_structure(caps, best_in_range); + guint best = static_cast<CapsCandidate *>(sorted->data)->index; + g_list_free(sorted); + + s = gst_caps_get_structure(caps, best); if (gst_structure_has_name(s, "video/x-raw")) { const gchar *format = gst_video_format_to_string(gst_format); @@ -529,6 +590,8 @@ void gst_libcamera_configure_stream_from_caps(StreamConfiguration &stream_cfg, stream_cfg.colorSpace = colorspace_from_colorimetry(colorimetry, transfer); } + + return true; } void gst_libcamera_get_framerate_from_caps(GstCaps *caps, diff --git a/src/gstreamer/gstlibcamera-utils.h b/src/gstreamer/gstlibcamera-utils.h index 35df56fb9..5ce0e839c 100644 --- a/src/gstreamer/gstlibcamera-utils.h +++ b/src/gstreamer/gstlibcamera-utils.h @@ -18,7 +18,7 @@ GstCaps *gst_libcamera_stream_formats_to_caps(const libcamera::StreamFormats &formats); GstCaps *gst_libcamera_stream_configuration_to_caps(const libcamera::StreamConfiguration &stream_cfg, GstVideoTransferFunction transfer); -void gst_libcamera_configure_stream_from_caps(libcamera::StreamConfiguration &stream_cfg, +bool gst_libcamera_configure_stream_from_caps(libcamera::StreamConfiguration &stream_cfg, GstCaps *caps, GstVideoTransferFunction *transfer); void gst_libcamera_get_framerate_from_caps(GstCaps *caps, GstStructure *element_caps); void gst_libcamera_clamp_and_set_frameduration(libcamera::ControlList &controls, diff --git a/src/gstreamer/gstlibcamerasrc.cpp b/src/gstreamer/gstlibcamerasrc.cpp index 9061f9163..66b31ce82 100644 --- a/src/gstreamer/gstlibcamerasrc.cpp +++ b/src/gstreamer/gstlibcamerasrc.cpp @@ -605,7 +605,8 @@ gst_libcamera_src_negotiate(GstLibcameraSrc *self) /* Fixate caps and configure the stream. */ caps = gst_caps_make_writable(caps); - gst_libcamera_configure_stream_from_caps(stream_cfg, caps, &transfer[i]); + if (!gst_libcamera_configure_stream_from_caps(stream_cfg, caps, &transfer[i])) + return false; gst_libcamera_get_framerate_from_caps(caps, element_caps); }
Existing code was preferring fixed size outputs over ones with ranges, resulting in raw output formats being preferred even when applications ("cheese" is one such example) aren't expecting them and subsequently fail. The revised version still prefers fixed size outputs over ones with ranges, but will prefer non-raw (meaning non-Bayer) formats where these are available. This still allows applications that explicitly request raw formats to get them, but other applications will normally get non-raw formats which they handle better. Fixes, for example, "cheese" on Raspberry Pi. Signed-off-by: David Plowman <david.plowman@raspberrypi.com> --- src/gstreamer/gstlibcamera-utils.cpp | 125 ++++++++++++++++++++------- src/gstreamer/gstlibcamera-utils.h | 2 +- src/gstreamer/gstlibcamerasrc.cpp | 3 +- 3 files changed, 97 insertions(+), 33 deletions(-)