libavcodec/adpcmenc.c File Reference

ADPCM encoders First version by Francois Revol (revol@free.fr) Fringe ADPCM codecs (e.g., DK3, DK4, Westwood) by Mike Melanson (melanson@pcisys.net). More...

#include "avcodec.h"
#include "get_bits.h"
#include "put_bits.h"
#include "bytestream.h"
#include "adpcm.h"
#include "adpcm_data.h"
#include "internal.h"

Go to the source code of this file.

Data Structures
struct	TrellisPath
struct	TrellisNode
struct	ADPCMEncodeContext
Defines
#define	FREEZE_INTERVAL   128
#define	STORE_NODE(NAME, STEP_INDEX)
#define	LOOP_NODES(NAME, STEP_TABLE, STEP_INDEX)
#define	ADPCM_ENCODER(id_, name_, long_name_)
Functions
static av_cold int	adpcm_encode_close (AVCodecContext *avctx)
static av_cold int	adpcm_encode_init (AVCodecContext *avctx)
static uint8_t	adpcm_ima_compress_sample (ADPCMChannelStatus *c, int16_t sample)
static uint8_t	adpcm_ima_qt_compress_sample (ADPCMChannelStatus *c, int16_t sample)
static uint8_t	adpcm_ms_compress_sample (ADPCMChannelStatus *c, int16_t sample)
static uint8_t	adpcm_yamaha_compress_sample (ADPCMChannelStatus *c, int16_t sample)
static void	adpcm_compress_trellis (AVCodecContext *avctx, const int16_t *samples, uint8_t *dst, ADPCMChannelStatus *c, int n)
static int	adpcm_encode_frame (AVCodecContext *avctx, AVPacket *avpkt, const AVFrame *frame, int *got_packet_ptr)
	ADPCM_ENCODER (AV_CODEC_ID_ADPCM_IMA_QT, adpcm_ima_qt,"ADPCM IMA QuickTime")
	ADPCM_ENCODER (AV_CODEC_ID_ADPCM_IMA_WAV, adpcm_ima_wav,"ADPCM IMA WAV")
	ADPCM_ENCODER (AV_CODEC_ID_ADPCM_MS, adpcm_ms,"ADPCM Microsoft")
	ADPCM_ENCODER (AV_CODEC_ID_ADPCM_SWF, adpcm_swf,"ADPCM Shockwave Flash")
	ADPCM_ENCODER (AV_CODEC_ID_ADPCM_YAMAHA, adpcm_yamaha,"ADPCM Yamaha")
Variables
static enum AVSampleFormat	sample_fmts []

---

Detailed Description

ADPCM encoders First version by Francois Revol (revol@free.fr) Fringe ADPCM codecs (e.g., DK3, DK4, Westwood) by Mike Melanson (melanson@pcisys.net).

See ADPCM decoder reference documents for codec information.

Definition in file adpcmenc.c.

---

Define Documentation

#define ADPCM_ENCODER	(	id_,
		name_,
		long_name_		)

Value:

AVCodec ff_ ## name_ ## _encoder = {                        \
    .name           = #name_,                               \
    .type           = AVMEDIA_TYPE_AUDIO,                   \
    .id             = id_,                                  \
    .priv_data_size = sizeof(ADPCMEncodeContext),           \
    .init           = adpcm_encode_init,                    \
    .encode2        = adpcm_encode_frame,                   \
    .close          = adpcm_encode_close,                   \
    .sample_fmts    = sample_fmts,                          \
    .long_name      = NULL_IF_CONFIG_SMALL(long_name_),     \
}

Definition at line 710 of file adpcmenc.c.

#define FREEZE_INTERVAL   128

Definition at line 60 of file adpcmenc.c.

Referenced by adpcm_compress_trellis(), adpcm_encode_init(), g722_encode_init(), and g722_encode_trellis().

#define LOOP_NODES	(	NAME,
		STEP_TABLE,
		STEP_INDEX		)

Value:

const int predictor = nodes[j]->sample1;\
                const int div = (sample - predictor) * 4 / STEP_TABLE;\
                int nmin = av_clip(div - range, -7, 6);\
                int nmax = av_clip(div + range, -6, 7);\
                if (nmin <= 0)\
                    nmin--; /* distinguish -0 from +0 */\
                if (nmax < 0)\
                    nmax--;\
                for (nidx = nmin; nidx <= nmax; nidx++) {\
                    const int nibble = nidx < 0 ? 7 - nidx : nidx;\
                    int dec_sample = predictor +\
                                    (STEP_TABLE *\
                                     ff_adpcm_yamaha_difflookup[nibble]) / 8;\
                    STORE_NODE(NAME, STEP_INDEX);\
                }

Referenced by adpcm_compress_trellis().

#define STORE_NODE	(	NAME,
		STEP_INDEX		)

Referenced by adpcm_compress_trellis(), and g722_encode_trellis().

---

Function Documentation

static void adpcm_compress_trellis	(	AVCodecContext *	avctx,
		const int16_t *	samples,
		uint8_t *	dst,
		ADPCMChannelStatus *	c,
		int	n
	)			[static]

Definition at line 275 of file adpcmenc.c.

static av_cold int adpcm_encode_close

(

AVCodecContext *

avctx

)

[static]

Definition at line 159 of file adpcmenc.c.

Referenced by adpcm_encode_init().

static int adpcm_encode_frame	(	AVCodecContext *	avctx,
		AVPacket *	avpkt,
		const AVFrame *	frame,
		int *	got_packet_ptr
	)			[static]

Definition at line 466 of file adpcmenc.c.

static av_cold int adpcm_encode_init

(

AVCodecContext *

avctx

)

[static]

Definition at line 64 of file adpcmenc.c.

ADPCM_ENCODER	(	AV_CODEC_ID_ADPCM_YAMAHA	,
		adpcm_yamaha	,
		"ADPCM Yamaha"
	)

ADPCM_ENCODER	(	AV_CODEC_ID_ADPCM_SWF	,
		adpcm_swf	,
		"ADPCM Shockwave Flash"
	)

ADPCM_ENCODER	(	AV_CODEC_ID_ADPCM_MS	,
		adpcm_ms	,
		"ADPCM Microsoft"
	)

ADPCM_ENCODER	(	AV_CODEC_ID_ADPCM_IMA_WAV	,
		adpcm_ima_wav	,
		"ADPCM IMA WAV"
	)

ADPCM_ENCODER	(	AV_CODEC_ID_ADPCM_IMA_QT	,
		adpcm_ima_qt	,
		"ADPCM IMA QuickTime"
	)

static uint8_t adpcm_ima_compress_sample	(	ADPCMChannelStatus *	c,
		int16_t	sample
	)			[inline, static]

Definition at line 174 of file adpcmenc.c.

static uint8_t adpcm_ima_qt_compress_sample	(	ADPCMChannelStatus *	c,
		int16_t	sample
	)			[inline, static]

Definition at line 187 of file adpcmenc.c.

static uint8_t adpcm_ms_compress_sample	(	ADPCMChannelStatus *	c,
		int16_t	sample
	)			[inline, static]

Definition at line 224 of file adpcmenc.c.

static uint8_t adpcm_yamaha_compress_sample	(	ADPCMChannelStatus *	c,
		int16_t	sample
	)			[inline, static]

Definition at line 253 of file adpcmenc.c.

---

Variable Documentation

enum AVSampleFormat sample_fmts[] [static]

Initial value:

 {
    AV_SAMPLE_FMT_S16, AV_SAMPLE_FMT_NONE
}

Definition at line 706 of file adpcmenc.c.

Referenced by av_abuffersink_params_alloc(), configure_output_audio_filter(), init_filters(), lavfi_read_header(), new_audio_stream(), print_codec(), and query_formats().