test: mux: add webvtt muxer unit tests

test/Makefile.am

@@ -56,6 +56,7 @@ check_PROGRAMS = \
 	test_modules_stream_out_pcr_sync \
 	test_modules_tls \
 	test_modules_stream_out_transcode \
+	test_modules_mux_webvtt \
 	$(NULL)
 
 if HAVE_GL
@@ -299,6 +300,9 @@ test_modules_stream_out_pcr_sync_SOURCES = modules/stream_out/pcr_sync.c \
 	../modules/stream_out/transcode/pcr_helper.c
 test_modules_stream_out_pcr_sync_LDADD = $(LIBVLCCORE)
 
+test_modules_mux_webvtt_SOURCES = modules/mux/webvtt.c
+test_modules_mux_webvtt_LDADD = $(LIBVLCCORE) $(LIBVLC)
+
 checkall:
 	$(MAKE) check_PROGRAMS="$(check_PROGRAMS) $(EXTRA_PROGRAMS)" check
 

test/modules/meson.build

@@ -165,3 +165,11 @@ vlc_tests += {
     'link_with' : [libvlccore],
     'module_depends' : vlc_plugins_targets.keys()
 }
+
+vlc_tests += {
+    'name' : 'test_modules_mux_webvtt',
+    'sources' : files('mux/webvtt.c'),
+    'suite' : ['modules', 'test_modules'],
+    'link_with' : [libvlc, libvlccore],
+    'module_depends' : vlc_plugins_targets.keys()
+}

test/modules/mux/webvtt.c

@@ -0,0 +1,207 @@
+/*****************************************************************************
+ * webvtt.c: WebVTT Muxer unit testing
+ *****************************************************************************
+ * Copyright (C) 2024 VideoLabs, VideoLAN and VLC Authors
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 2.1 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
+ *****************************************************************************/
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <vlc_common.h>
+
+#include <vlc_block.h>
+#include <vlc_plugin.h>
+#include <vlc_sout.h>
+
+#include "../../libvlc/test.h"
+#include "../lib/libvlc_internal.h"
+
+struct test_scenario
+{
+    vlc_fourcc_t codec;
+
+    unsigned bytes_reported;
+    const char *expected;
+
+    void (*report_sub)(block_t *);
+    void (*send_sub)(sout_mux_t *, sout_input_t *);
+};
+
+static struct test_scenario *CURRENT_SCENARIO = NULL;
+
+static ssize_t AccessOutWrite(sout_access_out_t *access, block_t *block)
+{
+    struct test_scenario *cb = access->p_sys;
+    assert(block->p_next == NULL);
+
+    cb->report_sub(block);
+
+    const ssize_t r = block->i_buffer;
+    block_ChainRelease(block);
+    return r;
+}
+
+static sout_access_out_t *CreateAccessOut(vlc_object_t *parent,
+                                          const struct test_scenario *cb)
+{
+    sout_access_out_t *access = vlc_object_create(parent, sizeof(*access));
+    if (unlikely(access == NULL))
+        return NULL;
+
+    access->psz_access = strdup("mock");
+    if (unlikely(access->psz_access == NULL))
+    {
+        vlc_object_delete(access);
+        return NULL;
+    }
+
+    access->p_cfg = NULL;
+    access->p_module = NULL;
+    access->p_sys = (void *)cb;
+    access->psz_path = NULL;
+
+    access->pf_control = NULL;
+    access->pf_read = NULL;
+    access->pf_seek = NULL;
+    access->pf_write = AccessOutWrite;
+    return access;
+}
+
+static void send_basic(sout_mux_t *mux, sout_input_t *input)
+{
+    for (vlc_tick_t time = VLC_TICK_0; time < VLC_TICK_FROM_MS(1300);
+         time += VLC_TICK_FROM_MS(300))
+    {
+        char *txt = strdup("Hello world");
+        assert(txt != NULL);
+
+        vlc_frame_t *spu = vlc_frame_heap_Alloc(txt, strlen(txt));
+        assert(spu != NULL);
+        spu->i_pts = time + VLC_TICK_FROM_SEC(15 * 60);
+        spu->i_length = VLC_TICK_INVALID;
+        const int status = sout_MuxSendBuffer(mux, input, spu);
+        assert(status == VLC_SUCCESS);
+    }
+}
+
+static void send_ephemer(sout_mux_t *mux, sout_input_t *input)
+{
+    for (vlc_tick_t time = VLC_TICK_0; time < VLC_TICK_FROM_MS(300);
+         time += VLC_TICK_FROM_MS(100))
+    {
+        char *txt = strdup("Hello world");
+        assert(txt != NULL);
+
+        vlc_frame_t *spu = vlc_frame_heap_Alloc(txt, strlen(txt));
+        assert(spu != NULL);
+        spu->i_pts = time;
+        spu->i_length = VLC_TICK_INVALID;
+        const int status = sout_MuxSendBuffer(mux, input, spu);
+        assert(status == VLC_SUCCESS);
+    }
+}
+
+static void default_report(block_t *sub)
+{
+    const char *expected =
+        CURRENT_SCENARIO->expected + CURRENT_SCENARIO->bytes_reported;
+
+    const int cmp =
+        strncmp(expected, (const char *)sub->p_buffer, sub->i_buffer);
+    assert(cmp == 0);
+    CURRENT_SCENARIO->bytes_reported += sub->i_buffer;
+}
+
+#define BASIC_TEXT                                                             \
+    "WEBVTT\n\n"                                                               \
+    "00:15:00.000 --> 00:15:00.300\n"                                          \
+    "Hello world\n\n"                                                          \
+    "00:15:00.300 --> 00:15:00.600\n"                                          \
+    "Hello world\n\n"                                                          \
+    "00:15:00.600 --> 00:15:00.900\n"                                          \
+    "Hello world\n\n"                                                          \
+    "00:15:00.900 --> 00:15:01.200\n"                                          \
+    "Hello world\n\n"
+
+#define EPHEMER_TEXT                                                           \
+    "WEBVTT\n\n"                                                               \
+    "00:00:00.000 --> 00:00:00.100\n"                                          \
+    "Hello world\n\n"                                                          \
+    "00:00:00.100 --> 00:00:00.200\n"                                          \
+    "Hello world\n\n"
+
+static struct test_scenario TEST_SCENARIOS[] = {
+    {
+        .codec = VLC_CODEC_TEXT,
+        .send_sub = send_basic,
+        .report_sub = default_report,
+        .expected = BASIC_TEXT,
+    },
+    {
+        .codec = VLC_CODEC_TEXT,
+        .send_sub = send_ephemer,
+        .report_sub = default_report,
+        .expected = EPHEMER_TEXT,
+    },
+};
+
+static void RunTests(libvlc_instance_t *instance)
+{
+    for (size_t i = 0; i < ARRAY_SIZE(TEST_SCENARIOS); ++i)
+    {
+        CURRENT_SCENARIO = &TEST_SCENARIOS[i];
+        sout_access_out_t *access = CreateAccessOut(
+            VLC_OBJECT(instance->p_libvlc_int), CURRENT_SCENARIO);
+        assert(access != NULL);
+
+        sout_mux_t *mux = sout_MuxNew(access, "webvtt");
+        assert(mux != NULL);
+
+        es_format_t fmt;
+        es_format_Init(&fmt, SPU_ES, CURRENT_SCENARIO->codec);
+        sout_input_t *input = sout_MuxAddStream(mux, &fmt);
+        assert(input != NULL);
+
+        // Disable mux caching.
+        mux->b_waiting_stream = false;
+
+        CURRENT_SCENARIO->send_sub(mux, input);
+
+        assert(CURRENT_SCENARIO->bytes_reported ==
+               strlen(CURRENT_SCENARIO->expected));
+
+        sout_MuxDeleteStream(mux, input);
+        sout_MuxDelete(mux);
+        sout_AccessOutDelete(access);
+    }
+}
+
+int main(void)
+{
+    test_init();
+
+    const char *const args[] = {
+        "-vvv",
+    };
+    libvlc_instance_t *vlc = libvlc_new(ARRAY_SIZE(args), args);
+    if (vlc == NULL)
+        return 1;
+
+    RunTests(vlc);
+
+    libvlc_release(vlc);
+}