This patch implements H264 support for VNC. The RFB protocol
extension is defined in:
https://github.com/rfbproto/rfbproto/blob/master/rfbproto.rst#open-h-264-encoding
Currently the Gstreamer x264enc plugin (software encoder) is used
to encode the video stream.
The gstreamer pipe is:
appsrc -> videoconvert -> x264enc -> appsink
Note: videoconvert is required for RGBx to YUV420 conversion.
The code still use the VNC server framebuffer change detection,
and only encodes and sends video frames if there are changes.
Signed-off-by: Dietmar Maurer <dietmar@proxmox.com>
---
ui/meson.build | 1 +
ui/vnc-enc-h264.c | 255 ++++++++++++++++++++++++++++++++++++++++++++++
ui/vnc-jobs.c | 53 +++++++---
ui/vnc.c | 37 ++++++-
ui/vnc.h | 21 ++++
5 files changed, 350 insertions(+), 17 deletions(-)
create mode 100644 ui/vnc-enc-h264.c
diff --git a/ui/meson.build b/ui/meson.build
index 35fb04cadf..34f1f33699 100644
--- a/ui/meson.build
+++ b/ui/meson.build
@@ -46,6 +46,7 @@ vnc_ss.add(files(
))
vnc_ss.add(zlib, jpeg)
vnc_ss.add(when: sasl, if_true: files('vnc-auth-sasl.c'))
+vnc_ss.add(when: gstreamer, if_true: files('vnc-enc-h264.c'))
system_ss.add_all(when: [vnc, pixman], if_true: vnc_ss)
system_ss.add(when: vnc, if_false: files('vnc-stubs.c'))
diff --git a/ui/vnc-enc-h264.c b/ui/vnc-enc-h264.c
new file mode 100644
index 0000000000..26e8c19270
--- /dev/null
+++ b/ui/vnc-enc-h264.c
@@ -0,0 +1,255 @@
+/*
+ * QEMU VNC display driver: H264 encoding
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include "qemu/osdep.h"
+#include "vnc.h"
+
+#include <gst/gst.h>
+
+static void destroy_encoder_context(VncState *vs)
+{
+ gst_clear_object(&vs->h264->source);
+ gst_clear_object(&vs->h264->convert);
+ gst_clear_object(&vs->h264->gst_encoder);
+ gst_clear_object(&vs->h264->sink);
+ gst_clear_object(&vs->h264->pipeline);
+}
+
+static bool create_encoder_context(VncState *vs, int w, int h)
+{
+ g_autoptr(GstCaps) source_caps = NULL;
+ GstStateChangeReturn state_change_ret;
+
+ g_assert(vs->h264 != NULL);
+
+ if (vs->h264->sink && w == vs->h264->width && h == vs->h264->height) {
+ return TRUE;
+ }
+
+ destroy_encoder_context(vs);
+
+ vs->h264->width = w;
+ vs->h264->height = h;
+
+ vs->h264->source = gst_element_factory_make("appsrc", "source");
+ if (!vs->h264->source) {
+ VNC_DEBUG("Could not create gst source\n");
+ goto error;
+ }
+
+ vs->h264->convert = gst_element_factory_make("videoconvert", "convert");
+ if (!vs->h264->convert) {
+ VNC_DEBUG("Could not create gst convert element\n");
+ goto error;
+ }
+
+ vs->h264->gst_encoder = gst_element_factory_make("x264enc", "gst-encoder");
+ if (!vs->h264->gst_encoder) {
+ VNC_DEBUG("Could not create gst x264 encoder\n");
+ goto error;
+ }
+
+ g_object_set(
+ vs->h264->gst_encoder,
+ "tune", 4, /* zerolatency */
+ /*
+ * fix for zerolatency with novnc (without, noVNC displays
+ * green stripes)
+ */
+ "threads", 1,
+ "pass", 5, /* Constant Quality */
+ "quantizer", 26,
+ /* avoid access unit delimiters (Nal Unit Type 9) - not required */
+ "aud", false,
+ NULL);
+
+ vs->h264->sink = gst_element_factory_make("appsink", "sink");
+ if (!vs->h264->sink) {
+ VNC_DEBUG("Could not create gst sink\n");
+ goto error;
+ }
+
+ vs->h264->pipeline = gst_pipeline_new("vnc-h264-pipeline");
+ if (!vs->h264->pipeline) {
+ VNC_DEBUG("Could not create gst pipeline\n");
+ goto error;
+ }
+
+ gst_object_ref(vs->h264->source);
+ if (!gst_bin_add(GST_BIN(vs->h264->pipeline), vs->h264->source)) {
+ gst_object_unref(vs->h264->source);
+ VNC_DEBUG("Could not add source to gst pipeline\n");
+ goto error;
+ }
+
+ gst_object_ref(vs->h264->convert);
+ if (!gst_bin_add(GST_BIN(vs->h264->pipeline), vs->h264->convert)) {
+ gst_object_unref(vs->h264->convert);
+ VNC_DEBUG("Could not add convert to gst pipeline\n");
+ goto error;
+ }
+
+ gst_object_ref(vs->h264->gst_encoder);
+ if (!gst_bin_add(GST_BIN(vs->h264->pipeline), vs->h264->gst_encoder)) {
+ gst_object_unref(vs->h264->gst_encoder);
+ VNC_DEBUG("Could not add encoder to gst pipeline\n");
+ goto error;
+ }
+
+ gst_object_ref(vs->h264->sink);
+ if (!gst_bin_add(GST_BIN(vs->h264->pipeline), vs->h264->sink)) {
+ gst_object_unref(vs->h264->sink);
+ VNC_DEBUG("Could not add sink to gst pipeline\n");
+ goto error;
+ }
+
+ source_caps = gst_caps_new_simple(
+ "video/x-raw",
+ "format", G_TYPE_STRING, "BGRx",
+ "framerate", GST_TYPE_FRACTION, 33, 1,
+ "width", G_TYPE_INT, w,
+ "height", G_TYPE_INT, h,
+ NULL);
+
+ if (!source_caps) {
+ VNC_DEBUG("Could not create source caps filter\n");
+ goto error;
+ }
+
+ g_object_set(vs->h264->source, "caps", source_caps, NULL);
+
+ if (gst_element_link_many(
+ vs->h264->source,
+ vs->h264->convert,
+ vs->h264->gst_encoder,
+ vs->h264->sink,
+ NULL
+ ) != TRUE) {
+ VNC_DEBUG("Elements could not be linked.\n");
+ goto error;
+ }
+
+ /* Start playing */
+ state_change_ret = gst_element_set_state(
+ vs->h264->pipeline, GST_STATE_PLAYING);
+
+ if (state_change_ret == GST_STATE_CHANGE_FAILURE) {
+ VNC_DEBUG("Unable to set the pipeline to the playing state.\n");
+ goto error;
+ }
+
+ return TRUE;
+
+ error:
+ destroy_encoder_context(vs);
+ return FALSE;
+}
+
+bool vnc_h264_encoder_init(VncState *vs)
+{
+ g_assert(vs->h264 == NULL);
+
+ vs->h264 = g_new0(VncH264, 1);
+
+ return true;
+}
+
+/*
+ * Returns the number of generated framebuffer updates,
+ * or -1 in case of errors
+ */
+int vnc_h264_send_framebuffer_update(VncState *vs)
+{
+ int n = 0;
+ int rdb_h264_flags = 0;
+ int width, height;
+ uint8_t *src_data_ptr = NULL;
+ size_t src_data_size;
+ GstFlowReturn flow_ret = GST_FLOW_ERROR;
+ GstBuffer *src_buffer = NULL;
+
+ g_assert(vs->h264 != NULL);
+ g_assert(vs->vd != NULL);
+ g_assert(vs->vd->server != NULL);
+
+ width = pixman_image_get_width(vs->vd->server);
+ height = pixman_image_get_height(vs->vd->server);
+
+ g_assert(width == vs->client_width);
+ g_assert(height == vs->client_height);
+
+ if (vs->h264->sink) {
+ if (width != vs->h264->width || height != vs->h264->height) {
+ rdb_h264_flags = 2;
+ }
+ } else {
+ rdb_h264_flags = 2;
+ }
+
+ if (!create_encoder_context(vs, width, height)) {
+ VNC_DEBUG("Create encoder context failed\n");
+ return -1;
+ }
+
+ g_assert(vs->h264->sink != NULL);
+
+ src_data_ptr = vnc_server_fb_ptr(vs->vd, 0, 0);
+ src_data_size = width * height * VNC_SERVER_FB_BYTES;
+
+ src_buffer = gst_buffer_new_wrapped_full(
+ 0, src_data_ptr, src_data_size, 0, src_data_size, NULL, NULL);
+
+ g_signal_emit_by_name(
+ vs->h264->source, "push-buffer", src_buffer, &flow_ret);
+
+ if (flow_ret != GST_FLOW_OK) {
+ VNC_DEBUG("gst appsrc push buffer failed\n");
+ return -1;
+ }
+
+ do {
+ GstSample *sample = NULL;
+ GstMapInfo map;
+ GstBuffer *out_buffer;
+
+ /* Retrieve the buffer */
+ g_signal_emit_by_name(vs->h264->sink, "try-pull-sample", 0, &sample);
+ if (!sample) {
+ break;
+ }
+ out_buffer = gst_sample_get_buffer(sample);
+ if (gst_buffer_map(out_buffer, &map, 0)) {
+ vnc_framebuffer_update(vs, 0, 0, width, height, VNC_ENCODING_H264);
+ vnc_write_s32(vs, map.size); /* write data length */
+ vnc_write_s32(vs, rdb_h264_flags); /* write flags */
+ rdb_h264_flags = 0;
+
+ VNC_DEBUG("GST vnc_h264_update send %ld\n", map.size);
+
+ vnc_write(vs, map.data, map.size);
+
+ gst_buffer_unmap(out_buffer, &map);
+
+ n += 1;
+ } else {
+ VNC_DEBUG("unable to map sample\n");
+ }
+ gst_sample_unref(sample);
+ } while (true);
+
+ return n;
+}
+
+void vnc_h264_clear(VncState *vs)
+{
+ if (!vs->h264) {
+ return;
+ }
+
+ destroy_encoder_context(vs);
+
+ g_clear_pointer(&vs->h264, g_free);
+}
diff --git a/ui/vnc-jobs.c b/ui/vnc-jobs.c
index fcca7ec632..75a3bbed3d 100644
--- a/ui/vnc-jobs.c
+++ b/ui/vnc-jobs.c
@@ -111,7 +111,7 @@ int vnc_job_add_rect(VncJob *job, int x, int y, int w, int h)
void vnc_job_push(VncJob *job)
{
vnc_lock_queue(queue);
- if (queue->exit || QLIST_EMPTY(&job->rectangles)) {
+ if (queue->exit) {
g_free(job);
} else {
QTAILQ_INSERT_TAIL(&queue->jobs, job, next);
@@ -193,6 +193,9 @@ static void vnc_async_encoding_start(VncState *orig, VncState *local)
local->zlib = orig->zlib;
local->hextile = orig->hextile;
local->zrle = orig->zrle;
+#ifdef CONFIG_GSTREAMER
+ local->h264 = orig->h264;
+#endif
local->client_width = orig->client_width;
local->client_height = orig->client_height;
}
@@ -204,6 +207,9 @@ static void vnc_async_encoding_end(VncState *orig, VncState *local)
orig->zlib = local->zlib;
orig->hextile = local->hextile;
orig->zrle = local->zrle;
+#ifdef CONFIG_GSTREAMER
+ orig->h264 = local->h264;
+#endif
orig->lossy_rect = local->lossy_rect;
}
@@ -284,25 +290,40 @@ static int vnc_worker_thread_loop(VncJobQueue *queue)
vnc_write_u16(&vs, 0);
vnc_lock_display(job->vs->vd);
- QLIST_FOREACH_SAFE(entry, &job->rectangles, next, tmp) {
- int n;
-
- if (job->vs->ioc == NULL) {
- vnc_unlock_display(job->vs->vd);
- /* Copy persistent encoding data */
- vnc_async_encoding_end(job->vs, &vs);
- goto disconnected;
- }
- if (vnc_worker_clamp_rect(&vs, job, &entry->rect)) {
- n = vnc_send_framebuffer_update(&vs, entry->rect.x, entry->rect.y,
- entry->rect.w, entry->rect.h);
+ if (QLIST_EMPTY(&job->rectangles)) {
+ /* Send full screen update (used by h264 encoder) */
+ int width = pixman_image_get_width(vs.vd->server);
+ int height = pixman_image_get_height(vs.vd->server);
+ int n = vnc_send_framebuffer_update(&vs, 0, 0, width, height);
+ if (n >= 0) {
+ n_rectangles += n;
+ }
+ } else {
+ QLIST_FOREACH_SAFE(entry, &job->rectangles, next, tmp) {
+ int n;
+
+ if (job->vs->ioc == NULL) {
+ vnc_unlock_display(job->vs->vd);
+ /* Copy persistent encoding data */
+ vnc_async_encoding_end(job->vs, &vs);
+ goto disconnected;
+ }
- if (n >= 0) {
- n_rectangles += n;
+ if (vnc_worker_clamp_rect(&vs, job, &entry->rect)) {
+ n = vnc_send_framebuffer_update(
+ &vs,
+ entry->rect.x,
+ entry->rect.y,
+ entry->rect.w,
+ entry->rect.h);
+
+ if (n >= 0) {
+ n_rectangles += n;
+ }
}
+ g_free(entry);
}
- g_free(entry);
}
trace_vnc_job_nrects(&vs, job, n_rectangles);
vnc_unlock_display(job->vs->vd);
diff --git a/ui/vnc.c b/ui/vnc.c
index 9e097dc4b4..ba71589c6f 100644
--- a/ui/vnc.c
+++ b/ui/vnc.c
@@ -970,6 +970,11 @@ int vnc_send_framebuffer_update(VncState *vs, int x, int y, int w, int h)
case VNC_ENCODING_ZYWRLE:
n = vnc_zywrle_send_framebuffer_update(vs, x, y, w, h);
break;
+#ifdef CONFIG_GSTREAMER
+ case VNC_ENCODING_H264:
+ n = vnc_h264_send_framebuffer_update(vs);
+ break;
+#endif
default:
vnc_framebuffer_update(vs, x, y, w, h, VNC_ENCODING_RAW);
n = vnc_raw_send_framebuffer_update(vs, x, y, w, h);
@@ -1152,6 +1157,14 @@ static int vnc_update_client(VncState *vs, int has_dirty)
return 0;
}
+ if (vs->vnc_encoding == VNC_ENCODING_H264) {
+ vs->job_update = vs->update;
+ vs->update = VNC_STATE_UPDATE_NONE;
+ vnc_job_push(vnc_job_new(vs)); /* fullscreen update */
+ vs->has_dirty = 0;
+ return 1;
+ }
+
vs->has_dirty += has_dirty;
if (!vnc_should_update(vs)) {
return 0;
@@ -1204,7 +1217,11 @@ static int vnc_update_client(VncState *vs, int has_dirty)
vs->job_update = vs->update;
vs->update = VNC_STATE_UPDATE_NONE;
- vnc_job_push(job);
+ if (QLIST_EMPTY(&job->rectangles)) {
+ g_free(job);
+ } else {
+ vnc_job_push(job);
+ }
vs->has_dirty = 0;
return n;
}
@@ -1324,6 +1341,10 @@ void vnc_disconnect_finish(VncState *vs)
vnc_tight_clear(vs);
vnc_zrle_clear(vs);
+#ifdef CONFIG_GSTREAMER
+ vnc_h264_clear(vs);
+#endif
+
#ifdef CONFIG_VNC_SASL
vnc_sasl_client_cleanup(vs);
#endif /* CONFIG_VNC_SASL */
@@ -2179,6 +2200,16 @@ static void set_encodings(VncState *vs, int32_t *encodings, size_t n_encodings)
vnc_set_feature(vs, VNC_FEATURE_ZYWRLE);
vs->vnc_encoding = enc;
break;
+#ifdef CONFIG_GSTREAMER
+ case VNC_ENCODING_H264:
+ if (vnc_h264_encoder_init(vs)) {
+ vnc_set_feature(vs, VNC_FEATURE_H264);
+ vs->vnc_encoding = enc;
+ } else {
+ VNC_DEBUG("vnc_h264_encoder_init failed\n");
+ }
+ break;
+#endif
case VNC_ENCODING_DESKTOPRESIZE:
vnc_set_feature(vs, VNC_FEATURE_RESIZE);
break;
@@ -4289,6 +4320,10 @@ int vnc_init_func(void *opaque, QemuOpts *opts, Error **errp)
Error *local_err = NULL;
char *id = (char *)qemu_opts_id(opts);
+#ifdef CONFIG_GSTREAMER
+ gst_init(NULL, NULL);
+#endif
+
assert(id);
vnc_display_init(id, &local_err);
if (local_err) {
diff --git a/ui/vnc.h b/ui/vnc.h
index acc53a2cc1..0fe9a9ab16 100644
--- a/ui/vnc.h
+++ b/ui/vnc.h
@@ -46,6 +46,10 @@
#include "vnc-enc-zrle.h"
#include "ui/kbd-state.h"
+#ifdef CONFIG_GSTREAMER
+#include <gst/gst.h>
+#endif
+
// #define _VNC_DEBUG 1
#ifdef _VNC_DEBUG
@@ -231,6 +235,14 @@ typedef struct VncZywrle {
int buf[VNC_ZRLE_TILE_WIDTH * VNC_ZRLE_TILE_HEIGHT];
} VncZywrle;
+#ifdef CONFIG_GSTREAMER
+typedef struct VncH264 {
+ GstElement *pipeline, *source, *gst_encoder, *sink, *convert;
+ size_t width;
+ size_t height;
+} VncH264;
+#endif
+
struct VncRect
{
int x;
@@ -344,6 +356,9 @@ struct VncState
VncHextile hextile;
VncZrle *zrle;
VncZywrle zywrle;
+#ifdef CONFIG_GSTREAMER
+ VncH264 *h264;
+#endif
Notifier mouse_mode_notifier;
@@ -404,6 +419,7 @@ enum {
#define VNC_ENCODING_TRLE 0x0000000f
#define VNC_ENCODING_ZRLE 0x00000010
#define VNC_ENCODING_ZYWRLE 0x00000011
+#define VNC_ENCODING_H264 0x00000032 /* 50 */
#define VNC_ENCODING_COMPRESSLEVEL0 0xFFFFFF00 /* -256 */
#define VNC_ENCODING_QUALITYLEVEL0 0xFFFFFFE0 /* -32 */
#define VNC_ENCODING_XCURSOR 0xFFFFFF10 /* -240 */
@@ -464,6 +480,7 @@ enum VncFeatures {
VNC_FEATURE_XVP,
VNC_FEATURE_CLIPBOARD_EXT,
VNC_FEATURE_AUDIO,
+ VNC_FEATURE_H264,
};
@@ -625,6 +642,10 @@ int vnc_zrle_send_framebuffer_update(VncState *vs, int x, int y, int w, int h);
int vnc_zywrle_send_framebuffer_update(VncState *vs, int x, int y, int w, int h);
void vnc_zrle_clear(VncState *vs);
+bool vnc_h264_encoder_init(VncState *vs);
+int vnc_h264_send_framebuffer_update(VncState *vs);
+void vnc_h264_clear(VncState *vs);
+
/* vnc-clipboard.c */
void vnc_server_cut_text_caps(VncState *vs);
void vnc_client_cut_text(VncState *vs, size_t len, uint8_t *text);
--
2.39.5On Wed, Apr 30, 2025 at 09:25:19AM +0200, Dietmar Maurer wrote:
> This patch implements H264 support for VNC. The RFB protocol
> extension is defined in:
>
> https://github.com/rfbproto/rfbproto/blob/master/rfbproto.rst#open-h-264-encoding
>
> Currently the Gstreamer x264enc plugin (software encoder) is used
> to encode the video stream.
>
> The gstreamer pipe is:
>
> appsrc -> videoconvert -> x264enc -> appsink
>
> Note: videoconvert is required for RGBx to YUV420 conversion.
>
> The code still use the VNC server framebuffer change detection,
> and only encodes and sends video frames if there are changes.
>
> Signed-off-by: Dietmar Maurer <dietmar@proxmox.com>
> ---
> ui/meson.build | 1 +
> ui/vnc-enc-h264.c | 255 ++++++++++++++++++++++++++++++++++++++++++++++
> ui/vnc-jobs.c | 53 +++++++---
> ui/vnc.c | 37 ++++++-
> ui/vnc.h | 21 ++++
> 5 files changed, 350 insertions(+), 17 deletions(-)
> create mode 100644 ui/vnc-enc-h264.c
> diff --git a/ui/vnc-enc-h264.c b/ui/vnc-enc-h264.c
> new file mode 100644
> index 0000000000..26e8c19270
> --- /dev/null
> +++ b/ui/vnc-enc-h264.c
> @@ -0,0 +1,255 @@
> +/*
> + * QEMU VNC display driver: H264 encoding
> + *
> + * SPDX-License-Identifier: GPL-2.0-or-later
> + */
> +
> +#include "qemu/osdep.h"
> +#include "vnc.h"
> +
> +#include <gst/gst.h>
> +
> +static void destroy_encoder_context(VncState *vs)
> +{
> + gst_clear_object(&vs->h264->source);
> + gst_clear_object(&vs->h264->convert);
> + gst_clear_object(&vs->h264->gst_encoder);
> + gst_clear_object(&vs->h264->sink);
> + gst_clear_object(&vs->h264->pipeline);
> +}
> +
> +static bool create_encoder_context(VncState *vs, int w, int h)
> +{
> + g_autoptr(GstCaps) source_caps = NULL;
> + GstStateChangeReturn state_change_ret;
> +
> + g_assert(vs->h264 != NULL);
> +
> + if (vs->h264->sink && w == vs->h264->width && h == vs->h264->height) {
> + return TRUE;
> + }
> +
> + destroy_encoder_context(vs);
> +
> + vs->h264->width = w;
> + vs->h264->height = h;
> +
> + vs->h264->source = gst_element_factory_make("appsrc", "source");
> + if (!vs->h264->source) {
> + VNC_DEBUG("Could not create gst source\n");
> + goto error;
> + }
> +
> + vs->h264->convert = gst_element_factory_make("videoconvert", "convert");
> + if (!vs->h264->convert) {
> + VNC_DEBUG("Could not create gst convert element\n");
> + goto error;
> + }
> +
> + vs->h264->gst_encoder = gst_element_factory_make("x264enc", "gst-encoder");
> + if (!vs->h264->gst_encoder) {
> + VNC_DEBUG("Could not create gst x264 encoder\n");
> + goto error;
> + }
> +
> + g_object_set(
> + vs->h264->gst_encoder,
> + "tune", 4, /* zerolatency */
> + /*
> + * fix for zerolatency with novnc (without, noVNC displays
> + * green stripes)
> + */
> + "threads", 1,
> + "pass", 5, /* Constant Quality */
> + "quantizer", 26,
> + /* avoid access unit delimiters (Nal Unit Type 9) - not required */
> + "aud", false,
> + NULL);
> +
> + vs->h264->sink = gst_element_factory_make("appsink", "sink");
> + if (!vs->h264->sink) {
> + VNC_DEBUG("Could not create gst sink\n");
> + goto error;
> + }
> +
> + vs->h264->pipeline = gst_pipeline_new("vnc-h264-pipeline");
> + if (!vs->h264->pipeline) {
> + VNC_DEBUG("Could not create gst pipeline\n");
> + goto error;
> + }
> +
> + gst_object_ref(vs->h264->source);
> + if (!gst_bin_add(GST_BIN(vs->h264->pipeline), vs->h264->source)) {
> + gst_object_unref(vs->h264->source);
> + VNC_DEBUG("Could not add source to gst pipeline\n");
> + goto error;
> + }
> +
> + gst_object_ref(vs->h264->convert);
> + if (!gst_bin_add(GST_BIN(vs->h264->pipeline), vs->h264->convert)) {
> + gst_object_unref(vs->h264->convert);
> + VNC_DEBUG("Could not add convert to gst pipeline\n");
> + goto error;
> + }
> +
> + gst_object_ref(vs->h264->gst_encoder);
> + if (!gst_bin_add(GST_BIN(vs->h264->pipeline), vs->h264->gst_encoder)) {
> + gst_object_unref(vs->h264->gst_encoder);
> + VNC_DEBUG("Could not add encoder to gst pipeline\n");
> + goto error;
> + }
> +
> + gst_object_ref(vs->h264->sink);
> + if (!gst_bin_add(GST_BIN(vs->h264->pipeline), vs->h264->sink)) {
> + gst_object_unref(vs->h264->sink);
> + VNC_DEBUG("Could not add sink to gst pipeline\n");
> + goto error;
> + }
> +
> + source_caps = gst_caps_new_simple(
> + "video/x-raw",
> + "format", G_TYPE_STRING, "BGRx",
> + "framerate", GST_TYPE_FRACTION, 33, 1,
> + "width", G_TYPE_INT, w,
> + "height", G_TYPE_INT, h,
> + NULL);
> +
> + if (!source_caps) {
> + VNC_DEBUG("Could not create source caps filter\n");
> + goto error;
> + }
> +
> + g_object_set(vs->h264->source, "caps", source_caps, NULL);
> +
> + if (gst_element_link_many(
> + vs->h264->source,
> + vs->h264->convert,
> + vs->h264->gst_encoder,
> + vs->h264->sink,
> + NULL
> + ) != TRUE) {
> + VNC_DEBUG("Elements could not be linked.\n");
> + goto error;
> + }
> +
> + /* Start playing */
> + state_change_ret = gst_element_set_state(
> + vs->h264->pipeline, GST_STATE_PLAYING);
> +
> + if (state_change_ret == GST_STATE_CHANGE_FAILURE) {
> + VNC_DEBUG("Unable to set the pipeline to the playing state.\n");
> + goto error;
> + }
> +
> + return TRUE;
> +
> + error:
> + destroy_encoder_context(vs);
> + return FALSE;
> +}
> +
> +bool vnc_h264_encoder_init(VncState *vs)
> +{
> + g_assert(vs->h264 == NULL);
> +
> + vs->h264 = g_new0(VncH264, 1);
> +
> + return true;
> +}
> +
> +/*
> + * Returns the number of generated framebuffer updates,
> + * or -1 in case of errors
> + */
> +int vnc_h264_send_framebuffer_update(VncState *vs)
> +{
> + int n = 0;
> + int rdb_h264_flags = 0;
> + int width, height;
> + uint8_t *src_data_ptr = NULL;
> + size_t src_data_size;
> + GstFlowReturn flow_ret = GST_FLOW_ERROR;
> + GstBuffer *src_buffer = NULL;
> +
> + g_assert(vs->h264 != NULL);
> + g_assert(vs->vd != NULL);
> + g_assert(vs->vd->server != NULL);
> +
> + width = pixman_image_get_width(vs->vd->server);
> + height = pixman_image_get_height(vs->vd->server);
> +
> + g_assert(width == vs->client_width);
> + g_assert(height == vs->client_height);
> +
> + if (vs->h264->sink) {
> + if (width != vs->h264->width || height != vs->h264->height) {
> + rdb_h264_flags = 2;
> + }
> + } else {
> + rdb_h264_flags = 2;
> + }
> +
> + if (!create_encoder_context(vs, width, height)) {
> + VNC_DEBUG("Create encoder context failed\n");
> + return -1;
> + }
> +
> + g_assert(vs->h264->sink != NULL);
> +
> + src_data_ptr = vnc_server_fb_ptr(vs->vd, 0, 0);
> + src_data_size = width * height * VNC_SERVER_FB_BYTES;
> +
> + src_buffer = gst_buffer_new_wrapped_full(
> + 0, src_data_ptr, src_data_size, 0, src_data_size, NULL, NULL);
> +
> + g_signal_emit_by_name(
> + vs->h264->source, "push-buffer", src_buffer, &flow_ret);
> +
> + if (flow_ret != GST_FLOW_OK) {
> + VNC_DEBUG("gst appsrc push buffer failed\n");
> + return -1;
> + }
> +
> + do {
> + GstSample *sample = NULL;
> + GstMapInfo map;
> + GstBuffer *out_buffer;
> +
> + /* Retrieve the buffer */
> + g_signal_emit_by_name(vs->h264->sink, "try-pull-sample", 0, &sample);
> + if (!sample) {
> + break;
> + }
> + out_buffer = gst_sample_get_buffer(sample);
> + if (gst_buffer_map(out_buffer, &map, 0)) {
> + vnc_framebuffer_update(vs, 0, 0, width, height, VNC_ENCODING_H264);
> + vnc_write_s32(vs, map.size); /* write data length */
> + vnc_write_s32(vs, rdb_h264_flags); /* write flags */
> + rdb_h264_flags = 0;
> +
> + VNC_DEBUG("GST vnc_h264_update send %ld\n", map.size);
> +
> + vnc_write(vs, map.data, map.size);
> +
> + gst_buffer_unmap(out_buffer, &map);
> +
> + n += 1;
> + } else {
> + VNC_DEBUG("unable to map sample\n");
> + }
> + gst_sample_unref(sample);
> + } while (true);
> +
> + return n;
> +}
> +
> +void vnc_h264_clear(VncState *vs)
> +{
> + if (!vs->h264) {
> + return;
> + }
> +
> + destroy_encoder_context(vs);
> +
> + g_clear_pointer(&vs->h264, g_free);
> +}
> diff --git a/ui/vnc.c b/ui/vnc.c
> index 9e097dc4b4..ba71589c6f 100644
> --- a/ui/vnc.c
> +++ b/ui/vnc.c
> @@ -4289,6 +4320,10 @@ int vnc_init_func(void *opaque, QemuOpts *opts, Error **errp)
> Error *local_err = NULL;
> char *id = (char *)qemu_opts_id(opts);
>
> +#ifdef CONFIG_GSTREAMER
> + gst_init(NULL, NULL);
This method aborts the process on failure. We need to use
gst_init_check(NULL, NULL, &err)
and report the 'err' result with error_report() so it
integrates with QEMU's normal error reporting mechanisms.
> @@ -625,6 +642,10 @@ int vnc_zrle_send_framebuffer_update(VncState *vs, int x, int y, int w, int h);
> int vnc_zywrle_send_framebuffer_update(VncState *vs, int x, int y, int w, int h);
> void vnc_zrle_clear(VncState *vs);
>
> +bool vnc_h264_encoder_init(VncState *vs);
> +int vnc_h264_send_framebuffer_update(VncState *vs);
> +void vnc_h264_clear(VncState *vs);
These ought to be wrapped in '#ifdef CONFIG_GSTREAMER' too, so that is
obvious they're conditionally available, and it'll trigger a compiler
error if someone tries to call them outside a matching #ifdef
> +
> /* vnc-clipboard.c */
> void vnc_server_cut_text_caps(VncState *vs);
> void vnc_client_cut_text(VncState *vs, size_t len, uint8_t *text);
> --
> 2.39.5
>
>
With regards,
Daniel
--
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