Compressed stream support. More...

Data Structures
struct	gavl_compression_info_t
	Compression format. More...

struct	gavl_packet_t
	Packet structure. More...

struct	gavl_stream_stats_t

Macros
#define	GAVL_COMPRESSION_HAS_P_FRAMES (1<<0)
	Set if not all frames are keyframes. More...

#define	GAVL_COMPRESSION_HAS_B_FRAMES (1<<1)
	Set if frames don't appear in presentation order. More...

#define	GAVL_COMPRESSION_HAS_FIELD_PICTURES (1<<2)
	Packets can consist of 2 consecutive fields. More...

#define	GAVL_COMPRESSION_SBR (1<<3)
	Samplerate got doubled by decoder, format and sample counts are for the upsampled rate. More...

#define	GAVL_COMPRESSION_BIG_ENDIAN (1<<4)
	Only in uncompressed gavf streams: Specifies that multibyte numbers are big endian. More...

#define	GAVL_BITRATE_VBR -1
	Use this to specify a VBR stream. More...

#define	GAVL_BITRATE_LOSSLESS -2
	Use this to specify a losslessly compressed stream. More...

#define	GAVL_PACKET_TYPE_I 0x01
	Packet is an I-frame. More...

#define	GAVL_PACKET_TYPE_P 0x02
	Packet is a P-frame. More...

#define	GAVL_PACKET_TYPE_B 0x03
	Packet is a B-frame. More...

#define	GAVL_PACKET_TYPE_MASK 0x03
	Mask for frame type. More...

#define	GAVL_PACKET_KEYFRAME (1<<2)
	Packet is a keyframe. More...

#define	GAVL_PACKET_LAST (1<<3)
	Packet is the last in the stream (only Xiph codecs need this flag) More...

#define	GAVL_PACKET_EXT (1<<4)
	Packet has extensions (used only in gavf files) More...

#define	GAVL_PACKET_REF (1<<5)
	B-frame used as reference (can't savely be skipped) More...

#define	GAVL_PACKET_NOOUTPUT (1<<6)
	Packet will produce no decoder output (e.g. VP8 alternate reference) More...

#define	GAVL_PACKET_FLAG_PRIV (1<<16)
	Private flag (defined outside of gavl) More...

#define	GAVL_PACKET_PADDING 32
	Packets are padded in memory with this many zero bytes. More...

Typedefs
typedef struct gavl_packet_pts_cache_s	gavl_packet_pts_cache_t

Enumerations
enum	gavl_codec_id_t { GAVL_CODEC_ID_NONE = 0 , GAVL_CODEC_ID_ALAW = 1 , GAVL_CODEC_ID_ULAW , GAVL_CODEC_ID_MP2 , GAVL_CODEC_ID_MP3 , GAVL_CODEC_ID_AC3 , GAVL_CODEC_ID_AAC , GAVL_CODEC_ID_VORBIS , GAVL_CODEC_ID_FLAC , GAVL_CODEC_ID_OPUS , GAVL_CODEC_ID_SPEEX , GAVL_CODEC_ID_DTS , GAVL_CODEC_ID_JPEG = 0x10000 , GAVL_CODEC_ID_PNG , GAVL_CODEC_ID_TIFF , GAVL_CODEC_ID_TGA , GAVL_CODEC_ID_MPEG1 , GAVL_CODEC_ID_MPEG2 , GAVL_CODEC_ID_MPEG4_ASP , GAVL_CODEC_ID_H264 , GAVL_CODEC_ID_THEORA , GAVL_CODEC_ID_DIRAC , GAVL_CODEC_ID_DV , GAVL_CODEC_ID_VP8 , GAVL_CODEC_ID_DIV3 , GAVL_CODEC_ID_DVDSUB = 0x20000 }
	Codec ID. More...

Functions
GAVL_PUBLIC void	gavl_compression_info_init (gavl_compression_info_t *info)
	Initialize a compression info. More...

GAVL_PUBLIC void	gavl_compression_info_free (gavl_compression_info_t *info)
	Free all dynamically allocated memory of a compression info. More...

GAVL_PUBLIC void	gavl_compression_info_dump (const gavl_compression_info_t *info)
	Dump a compression info to stderr. More...

GAVL_PUBLIC void	gavl_compression_info_dumpi (const gavl_compression_info_t *info, int num)
	Dump a compression info to stderr. More...

GAVL_PUBLIC void	gavl_compression_info_copy (gavl_compression_info_t dst, const gavl_compression_info_t src)
	Copy a compression info. More...

GAVL_PUBLIC void	gavl_append_xiph_header (uint8_t *global_header, uint32_t global_header_len, uint8_t *header, int header_len)
	Append a Xiph packet to a global header. More...

GAVL_PUBLIC uint8_t *	gavl_extract_xiph_header (uint8_t global_header, int global_header_len, int idx, int header_len)
	Extract a Xiph packet to a global header. More...

GAVL_PUBLIC const char *	gavl_compression_get_extension (gavl_codec_id_t id, int *separate)
	Get the file extension of the corresponding raw format. More...

GAVL_PUBLIC int	gavl_compression_need_pixelformat (gavl_codec_id_t id)
	Check if the compression supports multiple pixelformats. More...

const char *	gavl_compression_get_mimetype (const gavl_compression_info_t *ci)
	Get the mimetype for the corresponding elementary format. More...

GAVL_PUBLIC int	gavl_compression_constant_frame_samples (gavl_codec_id_t id)
	Check if an audio compression constant frame samples. More...

GAVL_PUBLIC int	gavl_compression_get_sample_size (gavl_codec_id_t id)
	Check if an audio compression size for each samples. More...

GAVL_PUBLIC const char *	gavl_compression_get_long_name (gavl_codec_id_t id)
	Return the long name of the compression. More...

GAVL_PUBLIC const char *	gavl_compression_get_short_name (gavl_codec_id_t id)
	Return the short name of the compression. More...

GAVL_PUBLIC gavl_codec_id_t	gavl_compression_from_short_name (const char *name)
	Get a compression from the short name. More...

GAVL_PUBLIC int	gavl_num_compressions ()
	Get the number of compression formats. More...

GAVL_PUBLIC gavl_codec_id_t	gavl_get_compression (int index)
	Get a compression format for a specified index. More...

GAVL_PUBLIC void	gavl_packet_init (gavl_packet_t *p)
	Initialize a packet. More...

GAVL_PUBLIC void	gavl_packet_alloc (gavl_packet_t *p, int len)
	Allocate memory for a packet. More...

GAVL_PUBLIC void	gavl_packet_free (gavl_packet_t *p)
	Free memory of a packet. More...

GAVL_PUBLIC void	gavl_packet_copy (gavl_packet_t dst, const gavl_packet_t src)
	Copy a packet. More...

GAVL_PUBLIC void	gavl_packet_copy_metadata (gavl_packet_t dst, const gavl_packet_t src)
	Copy metadata of a packet. More...

GAVL_PUBLIC void	gavl_packet_reset (gavl_packet_t *p)
	Reset a packet. More...

GAVL_PUBLIC void	gavl_packet_dump (const gavl_packet_t *p)
	Dump a packet to stderr. More...

GAVL_PUBLIC void	gavl_packet_save (const gavl_packet_t p, const char filename)
	Save a packet to a file. More...

GAVL_PUBLIC void	gavl_packet_to_videoframe (const gavl_packet_t p, gavl_video_frame_t f)

GAVL_PUBLIC void	gavl_stream_stats_init (gavl_stream_stats_t *)

GAVL_PUBLIC void	gavl_stream_stats_dump (const gavl_stream_stats_t *, int indent)

GAVL_PUBLIC void	gavl_stream_stats_update (gavl_stream_stats_t , const gavl_packet_t p)

GAVL_PUBLIC void	gavl_stream_stats_update_params (gavl_stream_stats_t *f, int64_t pts, int64_t duration, int data_len, int flags)

GAVL_PUBLIC void	gavl_stream_stats_apply_audio (gavl_stream_stats_t f, const gavl_audio_format_t fmt, gavl_compression_info_t ci, gavl_dictionary_t m)

GAVL_PUBLIC void	gavl_stream_stats_apply_video (gavl_stream_stats_t f, gavl_video_format_t fmt, gavl_compression_info_t ci, gavl_dictionary_t m)

GAVL_PUBLIC void	gavl_stream_stats_apply_subtitle (gavl_stream_stats_t f, gavl_dictionary_t m)

GAVL_PUBLIC void	gavl_stream_stats_apply_generic (gavl_stream_stats_t f, gavl_compression_info_t ci, gavl_dictionary_t *m)

GAVL_PUBLIC int	gavl_stream_get_stats (const gavl_dictionary_t s, gavl_stream_stats_t stats)

GAVL_PUBLIC void	gavl_stream_set_stats (gavl_dictionary_t s, const gavl_stream_stats_t stats)

GAVL_PUBLIC gavl_packet_pts_cache_t *	gavl_packet_pts_cache_create (int size)

GAVL_PUBLIC void	gavl_packet_pts_cache_destroy (gavl_packet_pts_cache_t *)

GAVL_PUBLIC void	gavl_packet_pts_cache_push (gavl_packet_pts_cache_t m, const gavl_packet_t pkt)

GAVL_PUBLIC int	gavl_packet_pts_cache_get_first (gavl_packet_pts_cache_t m, gavl_packet_t pkt)

GAVL_PUBLIC int	gavl_packet_pts_cache_get_by_pts (gavl_packet_pts_cache_t m, gavl_packet_t pkt, int64_t pts)

GAVL_PUBLIC void	gavl_packet_pts_cache_clear (gavl_packet_pts_cache_t *m)

Detailed Description

Compressed stream support.

gavl provides some structures and functions for handling compressed data packets. It is a completely independent API layer and has nothing to do with the uncompressed video and audio API. In particular the conversion between compressed and uncompressed data (i.e. codecs) are outside the scope of gavl. These are implemented in gmerlin-avdecoder and gmerlin encoding plugins.

Macro Definition Documentation

◆ GAVL_COMPRESSION_HAS_P_FRAMES

#define GAVL_COMPRESSION_HAS_P_FRAMES (1<<0)

Set if not all frames are keyframes.

◆ GAVL_COMPRESSION_HAS_B_FRAMES

#define GAVL_COMPRESSION_HAS_B_FRAMES (1<<1)

Set if frames don't appear in presentation order.

◆ GAVL_COMPRESSION_HAS_FIELD_PICTURES

#define GAVL_COMPRESSION_HAS_FIELD_PICTURES (1<<2)

Packets can consist of 2 consecutive fields.

◆ GAVL_COMPRESSION_SBR

#define GAVL_COMPRESSION_SBR (1<<3)

Samplerate got doubled by decoder, format and sample counts are for the upsampled rate.

◆ GAVL_COMPRESSION_BIG_ENDIAN

#define GAVL_COMPRESSION_BIG_ENDIAN (1<<4)

Only in uncompressed gavf streams: Specifies that multibyte numbers are big endian.

◆ GAVL_BITRATE_VBR

#define GAVL_BITRATE_VBR -1

Use this to specify a VBR stream.

◆ GAVL_BITRATE_LOSSLESS

#define GAVL_BITRATE_LOSSLESS -2

Use this to specify a losslessly compressed stream.

◆ GAVL_PACKET_TYPE_I

#define GAVL_PACKET_TYPE_I 0x01

Packet is an I-frame.

◆ GAVL_PACKET_TYPE_P

#define GAVL_PACKET_TYPE_P 0x02

Packet is a P-frame.

◆ GAVL_PACKET_TYPE_B

#define GAVL_PACKET_TYPE_B 0x03

Packet is a B-frame.

◆ GAVL_PACKET_TYPE_MASK

#define GAVL_PACKET_TYPE_MASK 0x03

Mask for frame type.

◆ GAVL_PACKET_KEYFRAME

#define GAVL_PACKET_KEYFRAME (1<<2)

Packet is a keyframe.

◆ GAVL_PACKET_LAST

#define GAVL_PACKET_LAST (1<<3)

Packet is the last in the stream (only Xiph codecs need this flag)

◆ GAVL_PACKET_EXT

#define GAVL_PACKET_EXT (1<<4)

Packet has extensions (used only in gavf files)

◆ GAVL_PACKET_REF

#define GAVL_PACKET_REF (1<<5)

B-frame used as reference (can't savely be skipped)

◆ GAVL_PACKET_NOOUTPUT

#define GAVL_PACKET_NOOUTPUT (1<<6)

Packet will produce no decoder output (e.g. VP8 alternate reference)

◆ GAVL_PACKET_FLAG_PRIV

#define GAVL_PACKET_FLAG_PRIV (1<<16)

Private flag (defined outside of gavl)

◆ GAVL_PACKET_PADDING

#define GAVL_PACKET_PADDING 32

Packets are padded in memory with this many zero bytes.

Enumeration Type Documentation

◆ gavl_codec_id_t

enum gavl_codec_id_t

Codec ID.

These are used as identifiers for the type of compression

Enumerator
GAVL_CODEC_ID_NONE	Unknown/unsupported compression format. In gavf files this signals that the stream consists of uncompressed gavl frames.
GAVL_CODEC_ID_ALAW	alaw 2:1
GAVL_CODEC_ID_ULAW	mu-law 2:1
GAVL_CODEC_ID_MP2	MPEG-1 audio layer II.
GAVL_CODEC_ID_MP3	MPEG-1/2 audio layer 3 CBR/VBR.
GAVL_CODEC_ID_AC3	AC3.
GAVL_CODEC_ID_AAC	AAC as stored in quicktime/mp4.
GAVL_CODEC_ID_VORBIS	Vorbis (segmented extradata and packets)
GAVL_CODEC_ID_FLAC	Flac (extradata contain a file header without comment and seektable)
GAVL_CODEC_ID_OPUS	Opus.
GAVL_CODEC_ID_SPEEX	Speex.
GAVL_CODEC_ID_DTS	DTS.
GAVL_CODEC_ID_JPEG	JPEG image.
GAVL_CODEC_ID_PNG	PNG image.
GAVL_CODEC_ID_TIFF	TIFF image.
GAVL_CODEC_ID_TGA	TGA image.
GAVL_CODEC_ID_MPEG1	MPEG-1 video.
GAVL_CODEC_ID_MPEG2	MPEG-2 video.
GAVL_CODEC_ID_MPEG4_ASP	MPEG-4 ASP (a.k.a. Divx4)
GAVL_CODEC_ID_H264	H.264 (Annex B)
GAVL_CODEC_ID_THEORA	Theora (segmented extradata)
GAVL_CODEC_ID_DIRAC	Complete DIRAC frames, sequence end code appended to last packet.
GAVL_CODEC_ID_DV	DV (several variants)
GAVL_CODEC_ID_VP8	VP8 (as used in webm)
GAVL_CODEC_ID_DIV3	Old style Divx (aka MSMPEG4V3)
GAVL_CODEC_ID_DVDSUB	DVD subtitles, palette is in header.

Function Documentation

◆ gavl_compression_info_init()

GAVL_PUBLIC void gavl_compression_info_init ( gavl_compression_info_t * info )

Initialize a compression info.

Parameters

info	A compression info

Use this for compression infos which are on the stack before using them.

◆ gavl_compression_info_free()

GAVL_PUBLIC void gavl_compression_info_free ( gavl_compression_info_t * info )

Free all dynamically allocated memory of a compression info.

Parameters

info	A compression info

◆ gavl_compression_info_dump()

GAVL_PUBLIC void gavl_compression_info_dump ( const gavl_compression_info_t * info )

Dump a compression info to stderr.

Parameters

info	A compression info

Use this for debugging

◆ gavl_compression_info_dumpi()

GAVL_PUBLIC void gavl_compression_info_dumpi	(	const gavl_compression_info_t *	info,
		int	num
	)

Dump a compression info to stderr.

Parameters

info	A compression info
indent	Indentation

Same as gavl_compression_info_dump but it puts indent whitespaces in front of each line.

◆ gavl_compression_info_copy()

GAVL_PUBLIC void gavl_compression_info_copy	(	gavl_compression_info_t *	dst,
		const gavl_compression_info_t *	src
	)

Copy a compression info.

Parameters

dst	Destination
src	Source

◆ gavl_append_xiph_header()

GAVL_PUBLIC void gavl_append_xiph_header	(	uint8_t **	global_header,
		uint32_t *	global_header_len,
		uint8_t *	header,
		int	header_len
	)

Append a Xiph packet to a global header.

Parameters

global_header	Global header (will be changed)
global_header_len	Global header length (will be changed)
header	header to append
header_len	length of header to append

◆ gavl_extract_xiph_header()

GAVL_PUBLIC uint8_t* gavl_extract_xiph_header	(	uint8_t *	global_header,
		int	global_header_len,
		int	idx,
		int *	header_len
	)

Extract a Xiph packet to a global header.

Parameters

global_header	Global header
global_header_len	Global header length
idx	Index of the packet (starting with 0)
header_len	Returns the length of the header

Returns: The data of the header packet

◆ gavl_compression_get_extension()

GAVL_PUBLIC const char* gavl_compression_get_extension	(	gavl_codec_id_t	id,
		int *	separate
	)

Get the file extension of the corresponding raw format.

Parameters

id	A codec ID
separate	If non-null returns 1 if each packet should be in a separate file

Returns: The file extension of the raw file or NULL

This function can be used for writing elementary streams to files. It returns a suitable file extension. If separate is 1, each packet should be written to a separate file. This basically means, that the codec corresponds to an image format.

Not all compression formats have a suitable elementary stream format, in this case NULL is returned for the extension. Most prominent examples are Vorbis and Theora, which can hardly exist outside an OGG container.

◆ gavl_compression_need_pixelformat()

GAVL_PUBLIC int gavl_compression_need_pixelformat ( gavl_codec_id_t id )

Check if the compression supports multiple pixelformats.

Parameters

id	A codec ID

Returns: 1 if the compression ID must be associated with a pixelformat, 0 else

This function can be used by decoding libraries to check if the compresison ID is sufficient or if the pixelformat must be valid in the associated video format.

◆ gavl_compression_get_mimetype()

const char* gavl_compression_get_mimetype ( const gavl_compression_info_t * ci )

Get the mimetype for the corresponding elementary format.

Parameters

ci	A compression info

Returns: The mimetype (can be NULL)

◆ gavl_compression_constant_frame_samples()

GAVL_PUBLIC int gavl_compression_constant_frame_samples ( gavl_codec_id_t id )

Check if an audio compression constant frame samples.

Parameters

id	A codec ID

Returns: 1 if the compression has the same number of samples in each frame, 0 else

◆ gavl_compression_get_sample_size()

GAVL_PUBLIC int gavl_compression_get_sample_size ( gavl_codec_id_t id )

Check if an audio compression size for each samples.

Parameters

id	A codec ID

Returns: The coded size of one sample or 0

◆ gavl_compression_get_long_name()

GAVL_PUBLIC const char* gavl_compression_get_long_name ( gavl_codec_id_t id )

Return the long name of the compression.

Parameters

id	A codec ID

Returns: The long name or NULL

◆ gavl_compression_get_short_name()

GAVL_PUBLIC const char* gavl_compression_get_short_name ( gavl_codec_id_t id )

Return the short name of the compression.

Parameters

id	A codec ID

Returns: The short name or NULL

◆ gavl_compression_from_short_name()

GAVL_PUBLIC gavl_codec_id_t gavl_compression_from_short_name ( const char * name )

Get a compression from the short name.

Parameters

A	short name

Returns: The codec ID (or GAVL_CODEC_ID_NONE)

◆ gavl_num_compressions()

GAVL_PUBLIC int gavl_num_compressions ( )

Get the number of compression formats.

Returns: The number of supported compresion formats

Use this with gavl_get_compression to enumerate all compression formats

◆ gavl_get_compression()

GAVL_PUBLIC gavl_codec_id_t gavl_get_compression ( int index )

Get a compression format for a specified index.

Parameters

index Index (starting with 0)

Returns: The compression format

Use this with gavl_num_compressions to enumerate all compression formats

◆ gavl_packet_init()

GAVL_PUBLIC void gavl_packet_init ( gavl_packet_t * p )

Initialize a packet.

Parameters

p A packet

◆ gavl_packet_alloc()

GAVL_PUBLIC void gavl_packet_alloc	(	gavl_packet_t *	p,
		int	len
	)

Allocate memory for a packet.

Parameters

p	A packet
len	Number of bytes you want to store in the packet

This function uses realloc(), which means that it preserves the data already contained in the packet.

◆ gavl_packet_free()

GAVL_PUBLIC void gavl_packet_free ( gavl_packet_t * p )

Free memory of a packet.

Parameters

p A packet

◆ gavl_packet_copy()

GAVL_PUBLIC void gavl_packet_copy	(	gavl_packet_t *	dst,
		const gavl_packet_t *	src
	)

Copy a packet.

Parameters

dst	Destination
src	Source

◆ gavl_packet_copy_metadata()

GAVL_PUBLIC void gavl_packet_copy_metadata	(	gavl_packet_t *	dst,
		const gavl_packet_t *	src
	)

Copy metadata of a packet.

Parameters

dst	Destination
src	Source

Like gavl_packet_copy but leaves the payload of dst untouched.

Since 1.5.0

◆ gavl_packet_reset()

GAVL_PUBLIC void gavl_packet_reset ( gavl_packet_t * p )

Reset a packet.

Parameters

p	Destination

Set fields to their default values

◆ gavl_packet_dump()

GAVL_PUBLIC void gavl_packet_dump ( const gavl_packet_t * p )

Dump a packet to stderr.

Parameters

p A packet

Use this for debugging

◆ gavl_packet_save()

GAVL_PUBLIC void gavl_packet_save	(	const gavl_packet_t *	p,
		const char *	filename
	)

Save a packet to a file.

Parameters

p	A packet
file	Filename

Use this for debugging

Data Structures

Macros

Typedefs

Enumerations

Functions

Detailed Description

Macro Definition Documentation

◆ GAVL_COMPRESSION_HAS_P_FRAMES

◆ GAVL_COMPRESSION_HAS_B_FRAMES

◆ GAVL_COMPRESSION_HAS_FIELD_PICTURES

◆ GAVL_COMPRESSION_SBR

◆ GAVL_COMPRESSION_BIG_ENDIAN

◆ GAVL_BITRATE_VBR

◆ GAVL_BITRATE_LOSSLESS

◆ GAVL_PACKET_TYPE_I

◆ GAVL_PACKET_TYPE_P

◆ GAVL_PACKET_TYPE_B

◆ GAVL_PACKET_TYPE_MASK

◆ GAVL_PACKET_KEYFRAME

◆ GAVL_PACKET_LAST

◆ GAVL_PACKET_EXT

◆ GAVL_PACKET_REF

◆ GAVL_PACKET_NOOUTPUT

◆ GAVL_PACKET_FLAG_PRIV

◆ GAVL_PACKET_PADDING

Enumeration Type Documentation

◆ gavl_codec_id_t

Function Documentation

◆ gavl_compression_info_init()

◆ gavl_compression_info_free()

◆ gavl_compression_info_dump()

◆ gavl_compression_info_dumpi()

◆ gavl_compression_info_copy()

◆ gavl_append_xiph_header()

◆ gavl_extract_xiph_header()

◆ gavl_compression_get_extension()

◆ gavl_compression_need_pixelformat()

◆ gavl_compression_get_mimetype()

◆ gavl_compression_constant_frame_samples()

◆ gavl_compression_get_sample_size()

◆ gavl_compression_get_long_name()

◆ gavl_compression_get_short_name()

◆ gavl_compression_from_short_name()

◆ gavl_num_compressions()

◆ gavl_get_compression()

◆ gavl_packet_init()

◆ gavl_packet_alloc()

◆ gavl_packet_free()

◆ gavl_packet_copy()

◆ gavl_packet_copy_metadata()

◆ gavl_packet_reset()

◆ gavl_packet_dump()

◆ gavl_packet_save()