ttadec.c

大名鼎鼎的CE下播放软件,TCPPMP的源代码!!!2410下可以流畅的解QVGA的H264,MPEG4等格式.

	init_buffer_read();

	pcm_buffer_size = PCM_BUFFER_LENGTH * ttainfo->BSIZE * ttainfo->NCH;
	maxvalue = (1UL << ttainfo->BPS) - 1;

	return 0;
}

void close_tta_file (tta_info *info) {
	
}

void player_stop () {
	if (seek_table) {
		free(seek_table);
		seek_table = NULL;
	}
}

int get_samples (byte *buffer) {
	unsigned int k, depth, unary, binary;
	byte *p = buffer;
	decoder *dec = tta;
	int *prev = cache;
	int value, res;

	for (res = 0; p < buffer + pcm_buffer_size;) {
		fltst *fst = &dec->fst;
		adapt *rice = &dec->rice;
		int *last = &dec->last;

		if (data_cur == framelen) {
			if (data_pos == fframes) break;
			if (framelen && done_buffer_read()) {
			    if (set_position(data_pos)) return -1;
			    if (res) break;
			}

			if (data_pos == fframes - 1 && lastlen)
				framelen = lastlen;
			else framelen = ttainfo->FRAMELEN;

			decoder_init(tta, ttainfo->NCH, ttainfo->BSIZE);
			data_pos++; data_cur = 0;
		}

		// decode Rice unsigned
		GET_UNARY(unary);

		switch (unary) {
		case 0: depth = 0; k = rice->k0; break;
		default:
			depth = 1; k = rice->k1;
			unary--;
		}

		if (k) {
			GET_BINARY(binary, k);
			value = (unary << k) + binary;
		} else value = unary;

		switch (depth) {
		case 1: 
			rice->sum1 += value - (rice->sum1 >> 4);
			if (rice->k1 > 0 && rice->sum1 < shift_16[rice->k1])
				rice->k1--;
			else if (rice->sum1 > shift_16[rice->k1 + 1])
				rice->k1++;
			value += bit_shift[rice->k0];
		default:
			rice->sum0 += value - (rice->sum0 >> 4);
			if (rice->k0 > 0 && rice->sum0 < shift_16[rice->k0])
				rice->k0--;
			else if (rice->sum0 > shift_16[rice->k0 + 1])
			rice->k0++;
		}

		value = DEC(value);

		// decompress stage 1: adaptive hybrid filter
		hybrid_filter(fst, &value);

		// decompress stage 2: fixed order 1 prediction
		switch (ttainfo->BSIZE) {
		case 1: value += PREDICTOR1(*last, 4); break;	// bps 8
		case 2: value += PREDICTOR1(*last, 5); break;	// bps 16
		case 3: value += PREDICTOR1(*last, 5); break;	// bps 24
		} *last = value;

		// check for errors
		if (abs(value) > maxvalue) {
			unsigned int tail =
				pcm_buffer_size / (ttainfo->BSIZE * ttainfo->NCH) - res;
			memset(buffer, 0, pcm_buffer_size);
			data_cur += tail; res += tail;
			break;
		}

		if (dec < tta + (ttainfo->NCH - 1)) {
			*prev++ = value; dec++;
		} else {
			*prev = value;
			if (ttainfo->NCH > 1) {
				int *r = prev - 1;
				for (*prev += *r/2; r >= cache; r--)
					*r = *(r + 1) - *r;
				for (r = cache; r < prev; r++)
					WRITE_BUFFER(r, ttainfo->BSIZE, p)
			}
			WRITE_BUFFER(prev, ttainfo->BSIZE, p)
			prev = cache;
			data_cur++; res++;
			dec = tta;
		}
	}

	return res;
}

/*
 * Description:	 ID3 tags manipulation routines
 *               Provides read access to ID3 tags v1.1, v2.3.x, v2.4.x
 *               Supported ID3v2 frames: Title, Artist, Album, Track,
 *               Year, Genre, Comment.
 *
 * Copyright (c) 2004 Alexander Djourik. All rights reserved.
 *
 */

static unsigned int unpack_sint28 (const char *ptr) {
	unsigned int value = 0;

	if (ptr[0] & 0x80) return 0;

	value =  value       | (ptr[0] & 0x7f);
	value = (value << 7) | (ptr[1] & 0x7f);
	value = (value << 7) | (ptr[2] & 0x7f);
	value = (value << 7) | (ptr[3] & 0x7f);

	return value;
}

static unsigned int unpack_sint32 (const char *ptr) {
	unsigned int value = 0;

	if (ptr[0] & 0x80) return 0;

	value = (value << 8) | ptr[0];
	value = (value << 8) | ptr[1];
	value = (value << 8) | ptr[2];
	value = (value << 8) | ptr[3];

	return value;
}

static int get_frame_id (const char *id) {
	if (!memcmp(id, "TIT2", 4)) return TIT2;	// Title
	if (!memcmp(id, "TPE1", 4)) return TPE1;	// Artist
	if (!memcmp(id, "TALB", 4)) return TALB;	// Album
	if (!memcmp(id, "TRCK", 4)) return TRCK;	// Track
	if (!memcmp(id, "TYER", 4)) return TYER;	// Year
	if (!memcmp(id, "TCON", 4)) return TCON;	// Genre
	if (!memcmp(id, "COMM", 4)) return COMM;	// Comment
	return 0;
}

#if 0

static int skip_id3_tag (tta_info *info) {
	id3v2_tag id3v2;
	int id3v2_size;

	////////////////////////////////////////
	// skip ID3v2 tag
	if (!info->Reader->Read(info->Reader, &id3v2, sizeof(id3v2_tag)))
		goto read_error;
	
	if (memcmp(id3v2.id, "ID3", 3)) {
		if (info->Reader->Seek(info->Reader, 0, SEEK_SET) < 0)
		    goto read_error;
		return 0;
	}

	if (id3v2.size[0] & 0x80) goto file_error;
	id3v2_size = unpack_sint28(id3v2.size);

	id3v2_size += (id3v2.flags &
		ID3_FOOTERPRESENT_FLAG) ? 20 : 10;
	info->Reader->Seek(info->Reader, id3v2_size, SEEK_SET);
	info->ID3.size = id3v2_size;

	return id3v2_size;

file_error:
	ttainfo->STATE = FILE_ERROR;
	return -1;

read_error:
	ttainfo->STATE = READ_ERROR;
	return -1;
}

#endif

static int read_id3_tags (tta_info *info) {
	id3v1_tag id3v1;
	id3v2_tag id3v2;
	id3v2_frame frame_header;
	int id3v2_size;
	char *buffer = NULL;
	char *ptr;

	////////////////////////////////////////
	// ID3v1 support
	if (info->Reader->Seek(info->Reader, -(int) sizeof(id3v1_tag),
		SEEK_END) < 0) goto read_error;

	if (!info->Reader->Read(info->Reader, &id3v1, sizeof(id3v1_tag))) 
    goto read_error;

	if (!memcmp (id3v1.id, "TAG", 3)) {
		memcpy(info->ID3.title, id3v1.title, 30);
		memcpy(info->ID3.artist, id3v1.artist, 30);
		memcpy(info->ID3.album, id3v1.album, 30);
		memcpy(info->ID3.year, id3v1.year, 4);
		memcpy(info->ID3.comment, id3v1.comment, 28);

		if (id3v1.genre > GENRES-1) id3v1.genre = 12;
		sprintf(info->ID3.track, "%02d", id3v1.track);
		if (id3v1.genre && id3v1.genre != 0xFF)
		    sprintf(info->ID3.genre, "%s", genre[id3v1.genre]);
		info->ID3.id3has |= 1;
	}

	if (info->Reader->Seek(info->Reader, 0, SEEK_SET) < 0)
		goto read_error;

	////////////////////////////////////////
	// ID3v2 minimal support
	if (!info->Reader->Read(info->Reader, &id3v2, sizeof(id3v2_tag)))
		goto read_error;
	
	if (memcmp(id3v2.id, "ID3", 3)) {
		if (info->Reader->Seek(info->Reader, 0, SEEK_SET) < 0)
		    goto read_error;
		return 0;
	}

	if (id3v2.size[0] & 0x80) goto file_error;
	id3v2_size = unpack_sint28(id3v2.size);

	if (!(buffer = (unsigned char *) malloc (id3v2_size))) {
		ttainfo->STATE = MEMORY_ERROR;
		goto read_done;
	}

	if ((id3v2.flags & ID3_UNSYNCHRONISATION_FLAG) ||
		(id3v2.flags & ID3_EXPERIMENTALTAG_FLAG) ||
		(id3v2.version < 3)) goto read_done;

	if (!info->Reader->Read(info->Reader, buffer, id3v2_size)) {
		free (buffer);
		goto read_error;
	}

	ptr = buffer;

	// skip extended header if present
	if (id3v2.flags & ID3_EXTENDEDHEADER_FLAG) {
		int offset = unpack_sint32(ptr);
		ptr += offset;
	}

	// read id3v2 frames
	while (ptr - buffer < id3v2_size) {
		char *data = NULL;
		int data_size, frame_id;
		int size = 0;

		// get frame header
		memcpy(&frame_header, ptr, sizeof(id3v2_frame));
		ptr += sizeof(id3v2_frame);
		data_size = unpack_sint32(frame_header.size);

		// skip unsupported frames
		if (!(frame_id = get_frame_id(frame_header.id)) ||
			frame_header.flags & FRAME_COMPRESSION_FLAG ||
			frame_header.flags & FRAME_ENCRYPTION_FLAG ||
			frame_header.flags & FRAME_UNSYNCHRONISATION_FLAG || (
			*ptr != FIELD_TEXT_ISO_8859_1 &&
			*ptr != FIELD_TEXT_UTF_8)) {
			ptr += data_size;
			continue;
		}

		data_size--; ptr++;

		switch (frame_id) {
		case TIT2:	data = info->ID3.title;
				size = sizeof(info->ID3.title) - 1; break;
		case TPE1:	data = info->ID3.artist;
				size = sizeof(info->ID3.artist) - 1; break;
		case TALB:	data = info->ID3.album;
				size = sizeof(info->ID3.album) - 1; break;
		case TRCK:	data = info->ID3.track;
				size = sizeof(info->ID3.track) - 1; break;
		case TYER:	data = info->ID3.year;
				size = sizeof(info->ID3.year) - 1; break;
		case TCON:	data = info->ID3.genre;
				size = sizeof(info->ID3.genre) - 1; break;
		case COMM:	data = info->ID3.comment;
				size = sizeof(info->ID3.comment) - 1;
				data_size -= 3; ptr += 3;

				// skip zero short description
				if (*ptr == 0) { data_size--; ptr++; }
				break;
		}

		if (data_size < size) size = data_size;
		memcpy(data, ptr, size); data[size] = '\0';
		ptr += data_size;
	}

	info->ID3.id3has |= 2;

read_done:
	if (buffer) free(buffer);

	id3v2_size += (id3v2.flags &
		ID3_FOOTERPRESENT_FLAG) ? 20 : 10;
	info->Reader->Seek(info->Reader, id3v2_size, SEEK_SET);
	info->ID3.size = id3v2_size;

	return id3v2_size;

file_error:
	ttainfo->STATE = FILE_ERROR;
	return -1;

read_error:
	ttainfo->STATE = READ_ERROR;
	return -1;
}

/* eof */