libavcodec/dpcm.c File Reference

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. More...

#include "libavutil/intreadwrite.h"
#include "avcodec.h"
#include "bytestream.h"

Go to the source code of this file.

Data Structures
struct	DPCMContext
Defines
#define	DPCM_DECODER(id_, name_, long_name_)
Functions
static av_cold int	dpcm_decode_init (AVCodecContext *avctx)
static int	dpcm_decode_frame (AVCodecContext *avctx, void *data, int *got_frame_ptr, AVPacket *avpkt)
	DPCM_DECODER (CODEC_ID_INTERPLAY_DPCM, interplay_dpcm,"DPCM Interplay")
	DPCM_DECODER (CODEC_ID_ROQ_DPCM, roq_dpcm,"DPCM id RoQ")
	DPCM_DECODER (CODEC_ID_SOL_DPCM, sol_dpcm,"DPCM Sol")
	DPCM_DECODER (CODEC_ID_XAN_DPCM, xan_dpcm,"DPCM Xan")
Variables
static const int16_t	interplay_delta_table []
static const int8_t	sol_table_old [16]
static const int8_t	sol_table_new [16]
static const int16_t	sol_table_16 [128]

---

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.

---

Define Documentation

#define DPCM_DECODER	(	id_,
		name_,
		long_name_		)

Value:

AVCodec ff_ ## name_ ## _decoder = {                        \
    .name           = #name_,                               \
    .type           = AVMEDIA_TYPE_AUDIO,                   \
    .id             = id_,                                  \
    .priv_data_size = sizeof(DPCMContext),                  \
    .init           = dpcm_decode_init,                     \
    .decode         = dpcm_decode_frame,                    \
    .capabilities   = CODEC_CAP_DR1,                        \
    .long_name      = NULL_IF_CONFIG_SMALL(long_name_),     \
}

Definition at line 331 of file dpcm.c.

---

Function Documentation

static int dpcm_decode_frame	(	AVCodecContext *	avctx,
		void *	data,
		int *	got_frame_ptr,
		AVPacket *	avpkt
	)			[static]

Definition at line 173 of file dpcm.c.

static av_cold int dpcm_decode_init

(

AVCodecContext *

avctx

)

[static]

Definition at line 115 of file dpcm.c.

DPCM_DECODER	(	CODEC_ID_XAN_DPCM	,
		xan_dpcm	,
		"DPCM Xan"
	)

DPCM_DECODER	(	CODEC_ID_SOL_DPCM	,
		sol_dpcm	,
		"DPCM Sol"
	)

DPCM_DECODER	(	CODEC_ID_ROQ_DPCM	,
		roq_dpcm	,
		"DPCM id RoQ"
	)

DPCM_DECODER	(	CODEC_ID_INTERPLAY_DPCM	,
		interplay_dpcm	,
		"DPCM Interplay"
	)

---

Variable Documentation

const int16_t interplay_delta_table[] [static]

Definition at line 52 of file dpcm.c.

Referenced by dpcm_decode_frame().

const int16_t 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 98 of file dpcm.c.

Referenced by dpcm_decode_frame().

const int8_t 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 93 of file dpcm.c.

Referenced by dpcm_decode_init().

const int8_t 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 88 of file dpcm.c.

Referenced by dpcm_decode_init().