dpcm.c File Reference

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Detailed Description

Assorted DPCM (differential pulse code modulation) audio codecs by Mike Melanson (melanson@pcisys.net) Xan DPCM decoder by Mario Brito (mbrito@student.dei.uc.pt) for more information on the specific data formats, visit: http://www.pcisys.net/~melanson/codecs/simpleaudio.html SOL DPCMs implemented by Konstantin Shishkov.

Note about using the Xan DPCM decoder: Xan DPCM is used in AVI files found in the Wing Commander IV computer game. These AVI files contain WAVEFORMAT headers which report the audio format as 0x01: raw PCM. Clearly incorrect. To detect Xan DPCM, you will probably have to special-case your AVI demuxer to use Xan DPCM if the file uses 'Xxan' (Xan video) for its video codec. Alternately, such AVI files also contain the fourcc 'Axan' in the 'auds' chunk of the AVI header.

Definition in file dpcm.c.

Go to the source code of this file.

Classes
struct	DPCMContext
Functions
static int	dpcm_decode_init (AVCodecContext *avctx)
static int	dpcm_decode_frame (AVCodecContext *avctx, void *data, int *data_size, uint8_t *buf, int buf_size)
	DPCM_DECODER (CODEC_ID_INTERPLAY_DPCM, interplay_dpcm)
	DPCM_DECODER (CODEC_ID_ROQ_DPCM, roq_dpcm)
	DPCM_DECODER (CODEC_ID_SOL_DPCM, sol_dpcm)
	DPCM_DECODER (CODEC_ID_XAN_DPCM, xan_dpcm)
Variables
static int	interplay_delta_table []
static const int	sol_table_old [16]
static const int	sol_table_new [16]
static const int	sol_table_16 [128]

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Function Documentation

static int dpcm_decode_init

(

AVCodecContext *

avctx

)

[static]

Definition at line 113 of file dpcm.c.

static int dpcm_decode_frame	(	AVCodecContext *	avctx,
		void *	data,
		int *	data_size,
		uint8_t *	buf,
		int	buf_size
	)			[static]

Definition at line 160 of file dpcm.c.

DPCM_DECODER	(	CODEC_ID_INTERPLAY_DPCM	,
		interplay_dpcm
	)

DPCM_DECODER	(	CODEC_ID_ROQ_DPCM	,
		roq_dpcm
	)

DPCM_DECODER	(	CODEC_ID_SOL_DPCM	,
		sol_dpcm
	)

DPCM_DECODER	(	CODEC_ID_XAN_DPCM	,
		xan_dpcm
	)

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Variable Documentation

int interplay_delta_table[] [static]

Definition at line 51 of file dpcm.c.

Referenced by dpcm_decode_frame().

const int sol_table_old[16] [static]

Initial value:

    { 0x0,  0x1,  0x2 , 0x3,  0x6,  0xA,  0xF, 0x15,
    -0x15, -0xF, -0xA, -0x6, -0x3, -0x2, -0x1, 0x0}

Definition at line 87 of file dpcm.c.

Referenced by dpcm_decode_init().

const int sol_table_new[16] [static]

Initial value:

    { 0x0,  0x1,  0x2,  0x3,  0x6,  0xA,  0xF,  0x15,
      0x0, -0x1, -0x2, -0x3, -0x6, -0xA, -0xF, -0x15}

Definition at line 91 of file dpcm.c.

Referenced by dpcm_decode_init().

const int sol_table_16[128] [static]

Initial value:

 {
    0x000, 0x008, 0x010, 0x020, 0x030, 0x040, 0x050, 0x060, 0x070, 0x080,
    0x090, 0x0A0, 0x0B0, 0x0C0, 0x0D0, 0x0E0, 0x0F0, 0x100, 0x110, 0x120,
    0x130, 0x140, 0x150, 0x160, 0x170, 0x180, 0x190, 0x1A0, 0x1B0, 0x1C0,
    0x1D0, 0x1E0, 0x1F0, 0x200, 0x208, 0x210, 0x218, 0x220, 0x228, 0x230,
    0x238, 0x240, 0x248, 0x250, 0x258, 0x260, 0x268, 0x270, 0x278, 0x280,
    0x288, 0x290, 0x298, 0x2A0, 0x2A8, 0x2B0, 0x2B8, 0x2C0, 0x2C8, 0x2D0,
    0x2D8, 0x2E0, 0x2E8, 0x2F0, 0x2F8, 0x300, 0x308, 0x310, 0x318, 0x320,
    0x328, 0x330, 0x338, 0x340, 0x348, 0x350, 0x358, 0x360, 0x368, 0x370,
    0x378, 0x380, 0x388, 0x390, 0x398, 0x3A0, 0x3A8, 0x3B0, 0x3B8, 0x3C0,
    0x3C8, 0x3D0, 0x3D8, 0x3E0, 0x3E8, 0x3F0, 0x3F8, 0x400, 0x440, 0x480,
    0x4C0, 0x500, 0x540, 0x580, 0x5C0, 0x600, 0x640, 0x680, 0x6C0, 0x700,
    0x740, 0x780, 0x7C0, 0x800, 0x900, 0xA00, 0xB00, 0xC00, 0xD00, 0xE00,
    0xF00, 0x1000, 0x1400, 0x1800, 0x1C00, 0x2000, 0x3000, 0x4000
}

Definition at line 95 of file dpcm.c.

Referenced by dpcm_decode_init().