Suppose you invoke gst-launch with this invalid pipeline:
```
$ gst-launch-1.0 videotestsrc num-buffers=10 ! x264enc name=enc ! mux.sink_0 \
mpegtsmux name=mux ! fakesink
0:00:00.018631594 351169 0xb523090 ERROR GST_PIPELINE
subprojects/gstreamer/gst/parse/grammar.y:1151:gst_parse_perform_link:
could not link enc to mux
WARNING: erroneous pipeline: could not link enc to mux
```
The error message you get is not very helpful. This is a pity, because
this is where the error comes from:
```c
static GstPad *
gst_base_ts_mux_request_new_pad (GstElement * element, GstPadTemplate * templ,
const gchar * name, const GstCaps * caps)
{ // [...]
GST_ELEMENT_ERROR (element, STREAM, MUX,
("Invalid Elementary stream PID (0x%02u < 0x40)", pid), (NULL));
return NULL;
```
mpegtsmux posted an error with an explanation of why the linking failed.
However, since the error ocurred within gst_parse_launchv(), gst-launch
could not have set a bus handler, and the error message got discarded.
This patch attempts to make gst-launch more user-friendly by setting a
temporary bus handler during early bin construction to catch error
messages like this.
The errors are logged as ERROR level in the GST_PIPELINE category.
However, this is not enough, as GST_LEVEL_DEFAULT defaults to
GST_LEVEL_NONE in releases. In other words, outside of the dev
environment, GStreamer won't print ERROR logs by default.
To make sure the errors can reach users of packaged versions of
GStreamer, a new AtomicRcBox-based struct is added: reason_receiver_t.
graph_t owns a reference to reason_receiver_t and so does the temporary
bus handler.
When the temporary bus handler receives an error message, the `reason`
field of `reason_receiver_t` is filled with the error message.
Later, when SET_ERROR() is called as a consequence of the operation that
posted the error having returned failure, the reason message is
extracted and added to the GError message.
This is how the resulting error would look in the example from above:
WARNING: erroneous pipeline: could not link enc to mux --
GstMpegTsMux <mux> posted an error message: Invalid Elementary
stream PID (0x00 < 0x40)
Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/8417>
This doesn't always bring visible issue, but is formally incorrect:
not chaining up means that the code doesn't trigger GstObject and
GstElement "constructed" implementations.
In particular both GstElement's and GstObject's classes in
"constructed" may sign up this object for tracing and
GstObject's class sets GST_OBJECT_FLAG_CONSTRUCTED flag.
If we don't chain up none of this is going to be executed.
For example, before the fix leaks tracer couldn't detect this leak:
```c
int main (int argc, char **argv) {
g_setenv ("GST_TRACERS", "leaks(name=all-leaks)", TRUE);
g_setenv ("GST_DEBUG", "GST_TRACER:7", TRUE);
g_setenv ("G_DEBUG", "fatal-warnings", TRUE);
gst_init (&argc, &argv);
// leak audiomixer: doesn't detect because it's based on the aggregator
gst_element_factory_make ("audiomixer", "Jerry");
// leak videoconvert: this one is detected fine because it's not
// based on the aggregator
//gst_element_factory_make ("videoconvert", "Tom");
gst_deinit ();
return 0;
}
// $ cc tst.c $(pkg-config --cflags --libs gstreamer-1.0) -o tst && ./tst
```
Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/8416>
In many places in the log tracer %d was used for data types we have
string format functions. This is especially problematic when the data
type is not immediately obvious to the reader (e.g. gboolean vs
GstFlowRet, where TRUE==1 but GST_FLOW_OK==0) or the values are not easy
to memorize (GST_STATE_CHANGE_PLAYING_TO_PAUSED==35).
This patch replaces all the integer codes with string representations so
that the logs are easier to understand by humans.
The formatting of GstBufferList by the log tracer is also updated to use
GST_PTR_FORMAT instead of a raw pointer, so the user can see the
timestamps, size and number of buffers.
Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/8414>
Suppose you're trying to debug why this pipeline doesn't work:
```
$ GST_DEBUG=GST_PIPELINE:DEBUG gst-launch-1.0 \
videotestsrc num-buffers=10 ! x264enc name=enc ! mux.sink_0 \
mpegtsmux name=mux ! fakesink
```
You will encounter this line in the logs:
> gst_parse_perform_link: linking some pad of GstX264Enc named enc to
> pad mux of GstMpegTsMux named mux (0/1) with caps "(NULL)"
It would seem that the element name is being read as a pad name as well,
and that made me wonder if the parsing was not working. However, it was
just a bug in the code printing that log. This patch fixes that bug.
Note that it is possible to specify more than one pad name for each side
of the link. For instance, the following is a valid pipeline that will
remux the video and audio of an MP4 file into MKV:
```
$ GST_DEBUG=GST_PIPELINE:DEBUG gst-launch \
filesrc location=input.mp4 ! qtdemux name=demux \
multiqueue name=mq \
matroskamux name=mux ! filesink location=output.mkv \
demux.video_0,audio_0 ! mq.sink_0,sink_1 \
mq.src_0,src_1 ! mux.video_0,audio_0
```
The new logging accomodates this by using a new utility function to join
strings of pad name lists instead of `PRETTY_PAD_NAME_FMT` (which only
supports one pad name). For example:
> linking pads {video_0, audio_0} of GstQTDemux named demux to pads
> {sink_0, sink_1} of GstMultiQueue named mq with caps "(NULL)"
Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/8415>
"undefined reference to `GST_TRACER_PAD_SEND_EVENT_PRE'
undefined reference to `GST_TRACER_PAD_SEND_EVENT_POST'"
errors are generated when trying to build GStreamer with
the following build configuration:
meson setup -Dgstreamer:tracer_hooks=false build
Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/8419>
The documentation was incorrectly referring to `GST_QUERY` and `GST_BIN`
as GstDebug category names. These two don't follow the pattern of the
rest, and instead are named `query` and `bin` respectively.
This can be verified from the source code of the _do_init macro in the
same gstlog.c file, and from gstbin.c and gstquery.c calls to
GST_DEBUG_CATEGORY_INIT().
Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/8365>
The third argument of the pad-chain-pre and pad-chain-post hooks are of type GstBuffer* and GstBufferList* respectively.
However, when I added do_chain_buffer_pre() and do_chain_buffer_post()
to gstlog.c I accidentally make them take GstFlowReturn -- almost
certainly as an artifact from duplicating the code of the _post()
variants, leading to erroneous log lines like this:
```
do_chain_buffer_pre:<vp9parse0:sink> 0:00:01.615378540, pad=<vp9parse0:sink>, res=-1073639680
```
This patch fixes that.
Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/8366>
Similar to de30de865cd, this allows to follow the flow of events as they
arrive to a pad rather than only when they are pushed to a peer.
The hook is installed in gst_pad_send_event_unchecked() instead of
gst_pad_send_event() because the latter is often omitted: that is the
case especifically in gst_pad_push_event_unchecked(), where most event
propagation occurs.
This patch also makes use of the new hooks in the log tracer to log the
begining and end of the send_event processing.
Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/8330>
Previously, the tracer pad-push-event was only signalled on
gst_pad_push_event(). However, the sticky event handling code in
GStreamer uses gst_pad_push_event_unchecked() instead, which meant those
events were not logged.
This patch extends the definition of the pad-push-event tracer to cover
both calls to gst_pad_push_event() and any direct calls to
gst_pad_push_event_unchecked() that skip the former inside GstPad
private code.
gst_pad_push_event_unchecked() returns GstFlowReturn instead of
gboolean like gst_pad_push_event(). To maintain API compatibility, the
GstFlowReturn is converted to gboolean.
Fixes https://gitlab.freedesktop.org/gstreamer/gstreamer/-/issues/4182
Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/8342>
If starting the internal clock fails we would still store a broken clock in the
cache despite it being unusable and never recovering.
Not storing it allows the application to simply create a new one at a later time
and have starting it retried.
Also signal to the application that such a clock is not synced.
Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/8334>
Commit de30de865cd added a hook for pad-chain-{pre,post} and
pad-chain-list-{pre,post}. As explained in that commit, hooking the
chain is helpful because it allows you to hook to buffer propagation in
both srcpads (pad-push) and sinkpads (pad-chain).
This patch uses the new hooks to log pad-chain in the log tracer.
Before, only pad-push was logged, so you could only follow the flow of
buffers through the srcpads.
Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/8329>
gst_sparse_file_read() is supposed to set @error when returning 0 but
in some cases was not.
Hopefully fix a crash in gst_download_buffer_read_buffer() which is
checking error->code when 0 is returned.
I'm not totally sure when this happens as I debugged this from a post
mortem crash but returning a generic error here seems the safe thing to
do.
Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/8321>
The generation script can fail to generate a configuration for the four
libraries where the documentation is not generated from gir, as it needs
to run pkg-config.
Only add the path to the configuration file to the sitemap once it has
successfully been dumped.
Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/8324>
With this patch, configure time is identical no matter whether doc is
enabled or not.
The configuration files also now contain explicitly-listed sources with
no wildcards.
For the four libraries where hotdoc needs to use clang to generate the
documentation (as opposed to the rest of the libraries where hotdoc uses
the gir), the script will call pkg-config to determine the appropriate
C flags.
This means a side effect of this patch is that pkg-config files are now
generated for the gstadaptivedemux and gstopencv libraries.
Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/8312>
