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-rw-r--r--sys/dxr3/ac3_padder.c255
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diff --git a/sys/dxr3/ac3_padder.c b/sys/dxr3/ac3_padder.c
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+/* GStreamer
+ * Copyright (C) 2003 Martin Soto <martinsoto@users.sourceforge.net>
+ *
+ * ac3_padder.c: Pad AC3 frames for use with an SPDIF interface.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#include <stdio.h>
+#include <string.h>
+
+#include "ac3_padder.h"
+
+#define IEC61937_DATA_TYPE_AC3 1
+
+struct frmsize_s
+{
+ unsigned short bit_rate;
+ unsigned short frm_size[3];
+};
+
+
+static const struct frmsize_s frmsizecod_tbl[64] =
+ {
+ { 32 ,{64 ,69 ,96 } },
+ { 32 ,{64 ,70 ,96 } },
+ { 40 ,{80 ,87 ,120 } },
+ { 40 ,{80 ,88 ,120 } },
+ { 48 ,{96 ,104 ,144 } },
+ { 48 ,{96 ,105 ,144 } },
+ { 56 ,{112 ,121 ,168 } },
+ { 56 ,{112 ,122 ,168 } },
+ { 64 ,{128 ,139 ,192 } },
+ { 64 ,{128 ,140 ,192 } },
+ { 80 ,{160 ,174 ,240 } },
+ { 80 ,{160 ,175 ,240 } },
+ { 96 ,{192 ,208 ,288 } },
+ { 96 ,{192 ,209 ,288 } },
+ { 112 ,{224 ,243 ,336 } },
+ { 112 ,{224 ,244 ,336 } },
+ { 128 ,{256 ,278 ,384 } },
+ { 128 ,{256 ,279 ,384 } },
+ { 160 ,{320 ,348 ,480 } },
+ { 160 ,{320 ,349 ,480 } },
+ { 192 ,{384 ,417 ,576 } },
+ { 192 ,{384 ,418 ,576 } },
+ { 224 ,{448 ,487 ,672 } },
+ { 224 ,{448 ,488 ,672 } },
+ { 256 ,{512 ,557 ,768 } },
+ { 256 ,{512 ,558 ,768 } },
+ { 320 ,{640 ,696 ,960 } },
+ { 320 ,{640 ,697 ,960 } },
+ { 384 ,{768 ,835 ,1152 } },
+ { 384 ,{768 ,836 ,1152 } },
+ { 448 ,{896 ,975 ,1344 } },
+ { 448 ,{896 ,976 ,1344 } },
+ { 512 ,{1024 ,1114 ,1536 } },
+ { 512 ,{1024 ,1115 ,1536 } },
+ { 576 ,{1152 ,1253 ,1728 } },
+ { 576 ,{1152 ,1254 ,1728 } },
+ { 640 ,{1280 ,1393 ,1920 } },
+ { 640 ,{1280 ,1394 ,1920 } }
+ };
+
+
+
+/* Go one byte forward in the input buffer. */
+#define ac3p_in_fw(padder) ((padder)->in_ptr++, (padder)->remaining--)
+
+/* Go one byte forward in the output buffer. */
+#define ac3p_out_fw(padder) ((padder)->out_ptr++, (padder)->bytes_to_copy--)
+
+
+/**
+ * ac3p_init
+ * @padder: The padder structure to initialize.
+ *
+ * Initializes an AC3 stream padder. This structure can be
+ * subsequently used to parse an AC3 stream and convert it to IEC958
+ * (S/PDIF) padded packets.
+ */
+extern void
+ac3p_init(ac3_padder *padder)
+{
+ const char sync[4] = { 0x72, 0xF8, 0x1F, 0x4E };
+
+ padder->state = AC3P_STATE_SYNC1;
+
+ /* No material to read yet. */
+ padder->remaining = 0;
+
+ /* Initialize the sync bytes in the frame. */
+ memcpy(padder->frame.header, sync, 4);
+}
+
+
+/**
+ * ac3_push_data
+ * @padder The padder structure.
+ * @data A pointer to a buffer with new data to parse. This should
+ * correspond to a new piece of a stream containing raw AC3 data.
+ * @size The number of available bytes in the buffer.
+ *
+ * Pushes a new buffer of data to be parsed by the ac3 padder. The
+ * ac3_parse() function will actually parse the data and report when
+ * new frames are found. This funcion should only be called once at
+ * the beginning of the parsing process, or when the ac3_parse()
+ * function returns the %AC3P_EVENT_PUSH event.
+ */
+extern void
+ac3p_push_data(ac3_padder *padder, guchar *data, guint size)
+{
+ padder->in_ptr = data;
+ padder->remaining = size;
+}
+
+
+/**
+ * ac3p_parse
+ * @padder The padder structure.
+ *
+ * Parses the bytes already pushed into the padder structure (see
+ * ac3p_push_data()) and returns an event value depending on the
+ * results of the parsing.
+ *
+ * Returns: %AC3P_EVENT_FRAME to indicate that a new AC3 was found and
+ * padded for IEC958 transmission. This frame can be read inmediatly
+ * with ac3p_frame(). %AC3P_EVENT_PUSH to indicate that new data from
+ * the input stream must be pushed into the padder using
+ * ac3p_push_data(). This function should be called again after
+ * pushing the data.
+ */
+extern int
+ac3p_parse(ac3_padder *padder)
+{
+ while (padder->remaining > 0) {
+ switch (padder->state) {
+ case AC3P_STATE_SYNC1:
+ if (*(padder->in_ptr) == 0x0b) {
+ /* The first sync byte was found. Go to the next state. */
+ padder->frame.sync_byte1 = 0x0b;
+ padder->state = AC3P_STATE_SYNC2;
+ }
+ ac3p_in_fw(padder);
+ break;
+
+ case AC3P_STATE_SYNC2:
+ if (*(padder->in_ptr) == 0x77) {
+ /* The second sync byte was seen right after the first. Go to
+ the next state. */
+ padder->frame.sync_byte2 = 0x77;
+ padder->state = AC3P_STATE_HEADER;
+
+ /* Skip one byte. */
+ ac3p_in_fw(padder);
+
+ /* Prepare for reading the header. */
+ padder->out_ptr = (guchar *) &(padder->frame.crc1);
+ /* Discount the 2 sync bytes from the header size. */
+ padder->bytes_to_copy = AC3P_AC3_HEADER_SIZE - 2;
+ }
+ else {
+ /* The second sync byte was not seen. Go back to the
+ first state. */
+ padder->state = AC3P_STATE_SYNC1;
+ }
+ break;
+
+ case AC3P_STATE_HEADER:
+ if (padder->bytes_to_copy > 0) {
+ /* Copy one byte. */
+ *(padder->out_ptr) = *(padder->in_ptr);
+ ac3p_in_fw(padder);
+ ac3p_out_fw(padder);
+ }
+ else {
+ int fscod;
+
+ /* The header is ready: */
+
+ fscod = (padder->frame.code >> 6) & 0x03;
+
+ /* Calculate the frame size. */
+ padder->ac3_frame_size =
+ 2 * frmsizecod_tbl[padder->frame.code & 0x3f].frm_size[fscod];
+
+ /* Set up the IEC header. */
+ if (padder->ac3_frame_size > 0) {
+ padder->frame.header[4] = IEC61937_DATA_TYPE_AC3;
+ }
+ else {
+ /* Don't know what it is, better be careful. */
+ padder->state = AC3P_STATE_SYNC1;
+ break;
+ }
+ padder->frame.header[5] = 0x00;
+ padder->frame.header[6] = (padder->ac3_frame_size*8) & 0xFF;
+ padder->frame.header[7] = ((padder->ac3_frame_size*8) >> 8) & 0xFF;
+
+ /* Prepare for reading the body. */
+ padder->bytes_to_copy = padder->ac3_frame_size - AC3P_AC3_HEADER_SIZE;
+ padder->state = AC3P_STATE_CONTENT;
+ }
+ break;
+
+ case AC3P_STATE_CONTENT:
+ if (padder->bytes_to_copy > 0) {
+ /* Copy one byte. */
+ *(padder->out_ptr) = *(padder->in_ptr);
+ ac3p_in_fw(padder);
+ ac3p_out_fw(padder);
+ }
+ else {
+ guint16 *ptr, i;
+
+ /* Frame ready. Prepare for output: */
+
+ /* Zero the non AC3 portion of the padded frame. */
+ memset(&(padder->frame.sync_byte1) + padder->ac3_frame_size, 0,
+ AC3P_IEC_FRAME_SIZE - AC3P_IEC_HEADER_SIZE - padder->ac3_frame_size);
+
+ /* Fix the byte order in the AC3 portion: */
+ ptr = (guint16 *) &(padder->frame.sync_byte1);
+ i = padder->ac3_frame_size / 2;
+ while (i > 0) {
+ *ptr = GUINT16_TO_BE(*ptr);
+ ptr++;
+ i--;
+ }
+
+ /* Start over again. */
+ padder->state = AC3P_STATE_SYNC1;
+
+ return AC3P_EVENT_FRAME;
+ }
+ break;
+ }
+ }
+
+ return AC3P_EVENT_PUSH;
+}
+
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