gstreamer/gst-libs/gst/audio/gstnonstreamaudiodecoder.h
2017-07-18 12:46:57 +01:00

412 lines
22 KiB
C

/* GStreamer
* Copyright (C) <2017> Carlos Rafael Giani <dv at pseudoterminal dot org>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library 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
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
#ifndef __GST_NONSTREAM_AUDIO_DECODER_H__
#define __GST_NONSTREAM_AUDIO_DECODER_H__
#include <gst/gst.h>
#include <gst/base/gstadapter.h>
#include <gst/audio/audio.h>
G_BEGIN_DECLS
typedef struct _GstNonstreamAudioDecoder GstNonstreamAudioDecoder;
typedef struct _GstNonstreamAudioDecoderClass GstNonstreamAudioDecoderClass;
/**
* GstNonstreamAudioOutputMode:
* @GST_NONSTREAM_AUDIO_OUTPUT_MODE_LOOPING: Playback position is moved back to the beginning of the loop
* @GST_NONSTREAM_AUDIO_OUTPUT_MODE_STEADY: Playback position increases steadily, even when looping
*
* The output mode defines how the output behaves with regards to looping. Either the playback position is
* moved back to the beginning of the loop, acting like a backwards seek, or it increases steadily, as if
* loop were "unrolled".
*/
typedef enum
{
GST_NONSTREAM_AUDIO_OUTPUT_MODE_LOOPING,
GST_NONSTREAM_AUDIO_OUTPUT_MODE_STEADY
} GstNonstreamAudioOutputMode;
/**
* GstNonstreamAudioSubsongMode:
* @GST_NONSTREAM_AUDIO_SUBSONG_MODE_SINGLE: Only the current subsong is played
* @GST_NONSTREAM_AUDIO_SUBSONG_MODE_ALL: All subsongs are played (current subsong index is ignored)
* @GST_NONSTREAM_AUDIO_SUBSONG_MODE_DECODER_DEFAULT: Use decoder specific default behavior
*
* The subsong mode defines how the decoder shall handle subsongs.
*/
typedef enum
{
GST_NONSTREAM_AUDIO_SUBSONG_MODE_SINGLE,
GST_NONSTREAM_AUDIO_SUBSONG_MODE_ALL,
GST_NONSTREAM_AUDIO_SUBSONG_MODE_DECODER_DEFAULT
} GstNonstreamAudioSubsongMode;
#define GST_TYPE_NONSTREAM_AUDIO_DECODER (gst_nonstream_audio_decoder_get_type())
#define GST_NONSTREAM_AUDIO_DECODER(obj) (G_TYPE_CHECK_INSTANCE_CAST((obj), GST_TYPE_NONSTREAM_AUDIO_DECODER, GstNonstreamAudioDecoder))
#define GST_NONSTREAM_AUDIO_DECODER_CAST(obj) ((GstNonstreamAudioDecoder *)(obj))
#define GST_NONSTREAM_AUDIO_DECODER_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST((klass), GST_TYPE_NONSTREAM_AUDIO_DECODER, GstNonstreamAudioDecoderClass))
#define GST_NONSTREAM_AUDIO_DECODER_GET_CLASS(obj) (G_TYPE_INSTANCE_GET_CLASS((obj), GST_TYPE_NONSTREAM_AUDIO_DECODER, GstNonstreamAudioDecoderClass))
#define GST_IS_NONSTREAM_AUDIO_DECODER(obj) (G_TYPE_CHECK_INSTANCE_TYPE((obj), GST_TYPE_NONSTREAM_AUDIO_DECODER))
#define GST_IS_NONSTREAM_AUDIO_DECODER_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE((klass), GST_TYPE_NONSTREAM_AUDIO_DECODER))
/**
* GST_NONSTREAM_AUDIO_DECODER_SINK_NAME:
*
* The name of the template for the sink pad.
*/
#define GST_NONSTREAM_AUDIO_DECODER_SINK_NAME "sink"
/**
* GST_NONSTREAM_AUDIO_DECODER_SRC_NAME:
*
* The name of the template for the source pad.
*/
#define GST_NONSTREAM_AUDIO_DECODER_SRC_NAME "src"
/**
* GST_NONSTREAM_AUDIO_DECODER_SINK_PAD:
* @obj: base nonstream audio codec instance
*
* Gives the pointer to the sink #GstPad object of the element.
*/
#define GST_NONSTREAM_AUDIO_DECODER_SINK_PAD(obj) (((GstNonstreamAudioDecoder *) (obj))->sinkpad)
/**
* GST_NONSTREAM_AUDIO_DECODER_SRC_PAD:
* @obj: base nonstream audio codec instance
*
* Gives the pointer to the source #GstPad object of the element.
*/
#define GST_NONSTREAM_AUDIO_DECODER_SRC_PAD(obj) (((GstNonstreamAudioDecoder *) (obj))->srcpad)
/**
* GST_NONSTREAM_AUDIO_DECODER_LOCK_MUTEX:
* @obj: base nonstream audio codec instance
*
* Locks the decoder mutex.
*
* Internally, the mutex is locked before one of the class vfuncs are
* called, when position and duration queries are handled, and when
* properties are set/retrieved.
*
* Derived classes should call lock during decoder related modifications
* (for example, setting/clearing filter banks), when at the same time
* audio might get decoded. An example are configuration changes that
* happen when properties are set. Properties might be set from another
* thread, so while the derived decoder is reconfigured, the mutex
* should be locked.
*/
#define GST_NONSTREAM_AUDIO_DECODER_LOCK_MUTEX(obj) g_mutex_lock(&(((GstNonstreamAudioDecoder *)(obj))->mutex))
#define GST_NONSTREAM_AUDIO_DECODER_UNLOCK_MUTEX(obj) g_mutex_unlock(&(((GstNonstreamAudioDecoder *)(obj))->mutex))
/**
* GstNonstreamAudioDecoder:
*
* The opaque #GstNonstreamAudioDecoder data structure.
*/
struct _GstNonstreamAudioDecoder
{
GstElement element;
/*< protected > */
/* source and sink pads */
GstPad *sinkpad, *srcpad;
/* loading information */
gint64 upstream_size;
gboolean loaded_mode;
GstAdapter *input_data_adapter;
/* subsong states */
guint current_subsong;
GstNonstreamAudioSubsongMode subsong_mode;
GstClockTime subsong_duration;
/* output states */
GstNonstreamAudioOutputMode output_mode;
gint num_loops;
gboolean output_format_changed;
GstAudioInfo output_audio_info;
/* The difference between these two values is: cur_pos_in_samples is
* used for the GstBuffer offsets, while num_decoded_samples is used
* for the segment base time values.
* cur_pos_in_samples is reset after seeking, looping (when output mode
* is LOOPING) and switching subsongs, while num_decoded is only reset
* to 0 after a flushing seek (because flushing seeks alter the
* pipeline's base_time). */
guint64 cur_pos_in_samples, num_decoded_samples;
GstSegment cur_segment;
gboolean discont;
/* metadata */
GstToc *toc;
/* allocation */
GstAllocator *allocator;
GstAllocationParams allocation_params;
/* thread safety */
GMutex mutex;
};
/**
* GstNonstreamAudioDecoderClass:
* @element_class: The parent class structure
* @seek: Optional.
* Called when a seek event is received by the parent class.
* new_position is a pointer to a GstClockTime integer which
* contains a position relative to the current subsong.
* Minimum is 0, maximum is the subsong length.
* After this function finishes, new_position is set to the
* actual new position (which may differ from the request
* position, depending on the decoder).
* @tell: Optional.
* Called when a position query is received by the parent class.
* The position that this function returns must be relative to
* the current subsong. Thus, the minimum is 0, and the maximum
* is the subsong length.
* @load_from_buffer: Required if loads_from_sinkpad is set to TRUE (the default value).
* Loads the media from the given buffer. The entire media is supplied at once,
* so after this call, loading should be finished. This function
* can also make use of a suggested initial subsong & subsong mode and initial
* playback position (but isn't required to). In case it chooses a different starting
* position, the function must pass this position to *initial_position.
* The subclass does not have to unref the input buffer; the base class does that
* already.
* @load_from_custom: Required if loads_from_sinkpad is set to FALSE.
* Loads the media in a way defined by the custom sink. Data is not supplied;
* the derived class has to handle this on its own. Otherwise, this function is
* identical to @load_from_buffer.
* @get_main_tags: Optional.
* Returns a tag list containing the main song tags, or NULL if there are
* no such tags. Returned tags will be unref'd. Use this vfunc instead of
* manually pushing a tag event downstream to avoid edge cases where not yet
* pushed sticky tag events get overwritten before they are pushed (can for
* example happen with decodebin if tags are pushed downstream before the
* decodebin pads are linked).
* @set_current_subsong: Optional.
* Sets the current subsong. This function is allowed to switch to a different
* subsong than the required one, and can optionally make use of the suggested initial
* position. In case it chooses a different starting position, the function must pass
* this position to *initial_position.
* This function switches the subsong mode to GST_NONSTREAM_AUDIO_SUBSONG_MODE_SINGLE
* automatically.
* If this function is implemented by the subclass, @get_current_subsong and
* @get_num_subsongs should be implemented as well.
* @get_current_subsong: Optional.
* Returns the current subsong.
* If the current subsong mode is not GST_NONSTREAM_AUDIO_SUBSONG_MODE_SINGLE, this
* function's return value is undefined.
* If this function is implemented by the subclass,
* @get_num_subsongs should be implemented as well.
* @get_num_subsongs: Optional.
* Returns the number of subsongs available.
* The return values 0 and 1 have a similar, but distinct, meaning.
* If this function returns 0, then this decoder does not support subsongs at all.
* @get_current_subsong must then also always return 0. In other words, this function
* either never returns 0, or never returns anything else than 0.
* A return value of 1 means that the media contains either only one or no subsongs
* (the entire song is then considered to be one single subsong). 1 also means that only
* this very media has no or just one subsong, and the decoder itself can
* support multiple subsongs.
* @get_subsong_duration: Optional.
* Returns the duration of a subsong. Returns GST_CLOCK_TIME_NONE if duration is unknown.
* @get_subsong_tags: Optional.
* Returns tags for a subsong, or NULL if there are no tags.
* Returned tags will be unref'd.
* @set_subsong_mode: Optional.
* Sets the current subsong mode. Since this might influence the current playback position,
* this function must set the initial_position integer argument to a defined value.
* If the playback position is not affected at all, it must be set to GST_CLOCK_TIME_NONE.
* If the subsong is restarted after the mode switch, it is recommended to set the value
* to the position in the playback right after the switch (or 0 if the subsongs are always
* reset back to the beginning).
* @set_num_loops: Optional.
* Sets the number of loops for playback. If this is called during playback,
* the subclass must set any internal loop counters to zero. A loop value of -1
* means infinite looping; 0 means no looping; and when the num_loops is greater than 0,
* playback should loop exactly num_loops times. If this function is implemented,
* @get_num_loops should be implemented as well. The function can ignore the given values
* and choose another; however, @get_num_loops should return this other value afterwards.
* It is up to the subclass to define where the loop starts and ends. It can mean that only
* a subset at the end or in the middle of a song is repeated, for example.
* If the current subsong mode is GST_NONSTREAM_AUDIO_SUBSONG_MODE_SINGLE, then the subsong
* is repeated this many times. If it is GST_NONSTREAM_AUDIO_SUBSONG_MODE_ALL, then all
* subsongs are repeated this many times. With GST_NONSTREAM_AUDIO_SUBSONG_MODE_DECODER_DEFAULT,
* the behavior is decoder specific.
* @get_num_loops: Optional.
* Returns the number of loops for playback.
* @get_supported_output_modes: Always required.
* Returns a bitmask containing the output modes the subclass supports.
* The mask is formed by a bitwise OR combination of integers, which can be calculated
* this way: 1 << GST_NONSTREAM_AUDIO_OUTPUT_MODE_<mode> , where mode is either STEADY or LOOPING
* @set_output_mode: Optional.
* Sets the output mode the subclass has to use. Unlike with most other functions, the subclass
* cannot choose a different mode; it must use the requested one.
* If the output mode is set to LOOPING, @gst_nonstream_audio_decoder_handle_loop
* must be called after playback moved back to the start of a loop.
* @decode: Always required.
* Allocates an output buffer, fills it with decoded audio samples, and must be passed on to
* *buffer . The number of decoded samples must be passed on to *num_samples.
* If decoding finishes or the decoding is no longer possible (for example, due to an
* unrecoverable error), this function returns FALSE, otherwise TRUE.
* @decide_allocation: Optional.
* Sets up the allocation parameters for allocating output
* buffers. The passed in query contains the result of the
* downstream allocation query.
* Subclasses should chain up to the parent implementation to
* invoke the default handler.
* @propose_allocation: Optional.
* Proposes buffer allocation parameters for upstream elements.
* Subclasses should chain up to the parent implementation to
* invoke the default handler.
*
* Subclasses can override any of the available optional virtual methods or not, as
* needed. At minimum, @load_from_buffer (or @load_from_custom), @get_supported_output_modes,
* and @decode need to be overridden.
*
* All functions are called with a locked decoder mutex.
*
* <note> If GST_ELEMENT_ERROR, GST_ELEMENT_WARNING, or GST_ELEMENT_INFO are called from
* inside one of these functions, it is strongly recommended to unlock the decoder mutex
* before and re-lock it after these macros to prevent potential deadlocks in case the
* application does something with the element when it receives an ERROR/WARNING/INFO
* message. Same goes for gst_element_post_message() calls and non-serialized events. </note>
*
* By default, this class works by reading media data from the sinkpad, and then commencing
* playback. Some decoders cannot be given data from a memory block, so the usual way of
* reading all upstream data and passing it to @load_from_buffer doesn't work then. In this case,
* set the value of loads_from_sinkpad to FALSE. This changes the way this class operates;
* it does not require a sinkpad to exist anymore, and will call @load_from_custom instead.
* One example of a decoder where this makes sense is UADE (Unix Amiga Delitracker Emulator).
* For some formats (such as TFMX), it needs to do the file loading by itself.
* Since most decoders can read input data from a memory block, the default value of
* loads_from_sinkpad is TRUE.
*/
struct _GstNonstreamAudioDecoderClass
{
GstElementClass element_class;
gboolean loads_from_sinkpad;
/*< public > */
/* virtual methods for subclasses */
gboolean (*seek) (GstNonstreamAudioDecoder * dec,
GstClockTime * new_position);
GstClockTime (*tell) (GstNonstreamAudioDecoder * dec);
gboolean (*load_from_buffer) (GstNonstreamAudioDecoder * dec,
GstBuffer * source_data,
guint initial_subsong,
GstNonstreamAudioSubsongMode initial_subsong_mode,
GstClockTime * initial_position,
GstNonstreamAudioOutputMode * initial_output_mode,
gint * initial_num_loops);
gboolean (*load_from_custom) (GstNonstreamAudioDecoder * dec,
guint initial_subsong,
GstNonstreamAudioSubsongMode initial_subsong_mode,
GstClockTime * initial_position,
GstNonstreamAudioOutputMode * initial_output_mode,
gint * initial_num_loops);
GstTagList * (*get_main_tags) (GstNonstreamAudioDecoder * dec);
gboolean (*set_current_subsong) (GstNonstreamAudioDecoder * dec,
guint subsong,
GstClockTime * initial_position);
guint (*get_current_subsong) (GstNonstreamAudioDecoder * dec);
guint (*get_num_subsongs) (GstNonstreamAudioDecoder * dec);
GstClockTime (*get_subsong_duration) (GstNonstreamAudioDecoder * dec,
guint subsong);
GstTagList * (*get_subsong_tags) (GstNonstreamAudioDecoder * dec,
guint subsong);
gboolean (*set_subsong_mode) (GstNonstreamAudioDecoder * dec,
GstNonstreamAudioSubsongMode mode,
GstClockTime * initial_position);
gboolean (*set_num_loops) (GstNonstreamAudioDecoder * dec,
gint num_loops);
gint (*get_num_loops) (GstNonstreamAudioDecoder * dec);
guint (*get_supported_output_modes) (GstNonstreamAudioDecoder * dec);
gboolean (*set_output_mode) (GstNonstreamAudioDecoder * dec,
GstNonstreamAudioOutputMode mode,
GstClockTime * current_position);
gboolean (*decode) (GstNonstreamAudioDecoder * dec,
GstBuffer ** buffer,
guint * num_samples);
gboolean (*negotiate) (GstNonstreamAudioDecoder * dec);
gboolean (*decide_allocation) (GstNonstreamAudioDecoder * dec,
GstQuery * query);
gboolean (*propose_allocation) (GstNonstreamAudioDecoder * dec,
GstQuery * query);
/*< private > */
gpointer _gst_reserved[GST_PADDING_LARGE];
};
GST_EXPORT
GType gst_nonstream_audio_decoder_get_type (void);
GST_EXPORT
void gst_nonstream_audio_decoder_handle_loop (GstNonstreamAudioDecoder * dec,
GstClockTime new_position);
GST_EXPORT
gboolean gst_nonstream_audio_decoder_set_output_format (GstNonstreamAudioDecoder * dec,
GstAudioInfo const *audio_info);
GST_EXPORT
gboolean gst_nonstream_audio_decoder_set_output_format_simple (GstNonstreamAudioDecoder * dec,
guint sample_rate,
GstAudioFormat sample_format,
guint num_channels);
GST_EXPORT
void gst_nonstream_audio_decoder_get_downstream_info (GstNonstreamAudioDecoder * dec,
GstAudioFormat * format,
gint * sample_rate,
gint * num_channels);
GST_EXPORT
GstBuffer *gst_nonstream_audio_decoder_allocate_output_buffer (GstNonstreamAudioDecoder * dec,
gsize size);
G_END_DECLS
#endif /* __GST_NONSTREAM_AUDIO_DECODER_H__ */