(Note: This commit also modifies obs-ffmpeg and obs-outputs)
API Changed:
obs_output_info::void (*stop)(void *data);
To:
obs_output_info::void (*stop)(void *data, uint64_t ts);
This fixes the long-time design flaw where obs_output_stop and the
output 'stop' callback would just shut down the output without
considering the timing of when obs_output_stop was used, discarding any
possible buffering and causing the output to get cut off at an
unexpected timing.
The 'stop' callback of obs_output_info now takes a timestamp with the
expectation that the output will use that timestamp to stop output data
in accordance to that timing. obs_output_stop now records the timestamp
at the time that the function is called and calls the 'stop' callback
with that timestamp. If needed, obs_output_force_stop will still stop
the output immediately without buffering.
Because output stop timing has been fixed, there is no need to send the
remaining packets in the queue because it now just waits for the stop
timing anyway.
There was no error checking when sending headers/metadata, so what would
happen is that if a header/metadata send failed (meaning the socket was
disconnected), it would continue to act as if it was still connected,
and it would block and lock up on the next send/recv call.
Not calling recv when data is received will accumulate data in the
internal recveive buffer until it's full, in which case is will stop
acknowledging. This can lead to unjustified disconnections.
If there was an attempt to destroy the rtmp-stream output while it was
already connecting and stopping at the same time, it would try to join
with the stop thread rather than with the connect thread. The connect
thread would then continue past destruction.
Sometimes stopping a connection can lock up due to data that still
remains to be sent, and this would lock up the thread requesting the
stop (typically the UI thread). So instead of locking up the calling
thread, spawn a new thread specifically for stopping so the calling
thread can continue uninterrupted. If the user attempts to reconnect,
it will wait for the stop thread to complete in the connect thread
before attempting to connect.
API changed from:
obs_source_info::get_name(void)
obs_output_info::get_name(void)
obs_encoder_info::get_name(void)
obs_service_info::get_name(void)
API changed to:
obs_source_info::get_name(void *type_data)
obs_output_info::get_name(void *type_data)
obs_encoder_info::get_name(void *type_data)
obs_service_info::get_name(void *type_data)
This allows the type data to be used when getting the name of the
object (useful for plugin wrappers primarily).
NOTE: Though a parameter was added, this is backward-compatible with
older plugins due to calling convention. The new parameter will simply
be ignored by older plugins, and the stack (if used) will be cleaned up
by the caller.
Reinstate flag checks in RTMP_Close that were erroneously removed.
Clear out the Link state before we establish a new connection. There is
too much state carried around during authentication that has no good
place to clear it in librtmp, which assumes a clean structure when the
connection is initially established.
When frames were dropped, it would also drop I-frames, which can mess
with the keyframe calculation of certain services that depend on
I-frames in their output protocol (such as HLS).
Certain RTMP services will support multi audio tracks via RTMP. This
updates librtmp with custom code that enables multiple streams per
connection to be used; each subsequent stream typically containing extra
audio tracks. The audio encoder names are used to indicate the names of
tracks, and the name of the tracks are used for the stream keys for
those subsequent tracks.
API changed:
--------------------------
void obs_output_set_audio_encoder(
obs_output_t *output,
obs_encoder_t *encoder);
obs_encoder_t *obs_output_get_audio_encoder(
const obs_output_t *output);
obs_encoder_t *obs_audio_encoder_create(
const char *id,
const char *name,
obs_data_t *settings);
Changed to:
--------------------------
/* 'idx' specifies the track index of the output */
void obs_output_set_audio_encoder(
obs_output_t *output,
obs_encoder_t *encoder,
size_t idx);
/* 'idx' specifies the track index of the output */
obs_encoder_t *obs_output_get_audio_encoder(
const obs_output_t *output,
size_t idx);
/* 'mixer_idx' specifies the mixer index to capture audio from */
obs_encoder_t *obs_audio_encoder_create(
const char *id,
const char *name,
obs_data_t *settings,
size_t mixer_idx);
Overview
--------------------------
This feature allows multiple audio mixers to be used at a time. This
capability was able to be added with surprisingly very little extra
overhead. Audio will not be mixed unless it's assigned to a specific
mixer, and mixers will not mix unless they have an active mix
connection.
Mostly this will be useful for being able to separate out specific audio
for recording versus streaming, but will also be useful for certain
streaming services that support multiple audio streams via RTMP.
I didn't want to use a variable amount of mixers due to the desire to
reduce heap allocations, so currently I set the limit to 4 simultaneous
mixers; this number can be increased later if needed, but honestly I
feel like it's just the right number to use.
Sources:
Sources can now specify which audio mixers their audio is mixed to; this
can be a single mixer or multiple mixers at a time. The
obs_source_set_audio_mixers function sets the audio mixer which an audio
source applies to. For example, 0xF would mean that the source applies
to all four mixers.
Audio Encoders:
Audio encoders now must specify which specific audio mixer they use when
they encode audio data.
Outputs:
Outputs that use encoders can now support multiple audio tracks at once
if they have the OBS_OUTPUT_MULTI_TRACK capability flag set. This is
mostly only useful for certain types of RTMP transmissions, though may
be useful for file formats that support multiple audio tracks as well
later on.
Waiting for the first packet to arrive before sending the headers helps
prevent issues with certain types of encoders that may not get their
header/SEI until the first packet has been received.
Typedef pointers are unsafe. If you do:
typedef struct bla *bla_t;
then you cannot use it as a constant, such as: const bla_t, because
that constant will be to the pointer itself rather than to the
underlying data. I admit this was a fundamental mistake that must
be corrected.
All typedefs that were pointer types will now have their pointers
removed from the type itself, and the pointers will be used when they
are actually used as variables/parameters/returns instead.
This does not break ABI though, which is pretty nice.
