upipe-modules: add interlacing pipe

Add upipe_interlace pipe to preform temporal field interlacing.

Author: quarium

include/upipe-modules/upipe_interlace.h

@@ -0,0 +1,128 @@
+/*
+ * Copyright (C) 2026 EasyTools
+ *
+ * Authors: Arnaud de Turckheim
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+/** @file
+ * @short Upipe interlacing module
+ */
+
+#ifndef _UPIPE_MODULES_UPIPE_INTERLACE_H_
+/** @hidden */
+#define _UPIPE_MODULES_UPIPE_INTERLACE_H_
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include "upipe/upipe.h"
+
+#define UPIPE_INTERLACE_SIGNATURE UBASE_FOURCC('i','n','t','l')
+
+/** @This extends upipe_command with specific commands for interlace pipes. */
+enum upipe_interlace_command {
+    UPIPE_INTERLACE_SENTINEL = UPIPE_CONTROL_LOCAL,
+
+    /** set top field first output (bool) */
+    UPIPE_INTERLACE_SET_TFF,
+    /** get the configured value for top field first output (bool *) */
+    UPIPE_INTERLACE_GET_TFF,
+    /** set field drop (bool) */
+    UPIPE_INTERLACE_SET_DROP,
+    /** get the configured value for field drop (bool *) */
+    UPIPE_INTERLACE_GET_DROP,
+};
+
+/** @This converts @ref upipe_interlace_command to a string.
+ *
+ * @param command command to convert
+ * @return a string or NULL if invalid
+ */
+static inline const char *upipe_interlace_command_str(int command)
+{
+    switch ((enum upipe_interlace_command)command) {
+        UBASE_CASE_TO_STR(UPIPE_INTERLACE_SET_TFF);
+        UBASE_CASE_TO_STR(UPIPE_INTERLACE_GET_TFF);
+        UBASE_CASE_TO_STR(UPIPE_INTERLACE_SET_DROP);
+        UBASE_CASE_TO_STR(UPIPE_INTERLACE_GET_DROP);
+        case UPIPE_INTERLACE_SENTINEL: break;
+    }
+    return NULL;
+}
+
+/** @This sets the top field first output.
+ *
+ * @param upipe description structure of the pipe
+ * @param tff true for top field first, false for bottom field first
+ * @return an error code
+ */
+static inline int upipe_interlace_set_tff(struct upipe *upipe, bool tff)
+{
+    return upipe_control(upipe, UPIPE_INTERLACE_SET_TFF,
+                         UPIPE_INTERLACE_SIGNATURE, tff ? 1 : 0);
+}
+
+/** @This gets the top field first output configuration.
+ *
+ * @param upipe description structure of the pipe
+ * @param tff filled with the configured value
+ * @return an error code
+ */
+static inline int upipe_interlace_get_tff(struct upipe *upipe, bool *tff)
+{
+    return upipe_control(upipe, UPIPE_INTERLACE_GET_TFF,
+                         UPIPE_INTERLACE_SIGNATURE, tff);
+}
+
+/** @This sets field drop.
+ *
+ * If set to true, two frames are merged into one, keeping one field
+ * of each, so the output frame rate will be divided by two.
+ *
+ * 1111  2222  3333  4444  -> 1111  3333
+ *  1111  2222  3333  4444     2222  4444
+ * 1111  2222  3333  4444     1111  3333
+ *  1111  2222  3333  4444     2222  4444
+ *
+ * If set to false, each frame is merged with the previous and the
+ * next so the output frame rate is unchanged.
+ *
+ * 1111  2222  3333  4444  -> 1111  2222  3333  4444
+ *  1111  2222  3333  4444     2222  3333  4444  5555
+ * 1111  2222  3333  4444     1111  2222  3333  4444
+ *  1111  2222  3333  4444     2222  3333  4444  5555
+ *
+ * @param upipe description structure of the pipe
+ * @param drop true for dropping field
+ * @return an error code
+ */
+static inline int upipe_interlace_set_drop(struct upipe *upipe, bool drop)
+{
+    return upipe_control(upipe, UPIPE_INTERLACE_SET_DROP,
+                         UPIPE_INTERLACE_SIGNATURE, drop ? 1 : 0);
+}
+
+/** @This gets the field drop configuration.
+ *
+ * @param upipe description structure of the pipe
+ * @param drop filled with the configured value
+ * @return an error code
+ */
+static inline int upipe_interlace_get_drop(struct upipe *upipe, bool *drop)
+{
+    return upipe_control(upipe, UPIPE_INTERLACE_GET_DROP,
+                         UPIPE_INTERLACE_SIGNATURE, drop);
+}
+
+/** @This returns the management structure for all interlace pipes.
+ *
+ * @return pointer to manager
+ */
+struct upipe_mgr *upipe_interlace_mgr_alloc(void);
+
+#ifdef __cplusplus
+}
+#endif
+#endif

lib/upipe-modules/Build.mk

@@ -35,6 +35,7 @@ libupipe_modules-includes = \
     upipe_htons.h \
     upipe_http_source.h \
     upipe_idem.h \
+    upipe_interlace.h \
     upipe_m3u_reader.h \
     upipe_match_attr.h \
     upipe_multicat_probe.h \
@@ -116,6 +117,7 @@ libupipe_modules-src = \
     upipe_htons.c \
     upipe_http_source.c \
     upipe_idem.c \
+    upipe_interlace.c \
     upipe_m3u_reader.c \
     upipe_match_attr.c \
     upipe_multicat_probe.c \