Initial revision

CVS patchset: 1
CVS date: 2001/04/18 22:33:39

1 files changed, 235 insertions, 0 deletions

diff --git a/src/libmpeg2/header.c b/src/libmpeg2/header.c
new file mode 100644
index 000000000..e021b2f8e
--- /dev/null
+++ b/src/libmpeg2/header.c
@@ -0,0 +1,235 @@
+/*
+ * slice.c
+ * Copyright (C) 1999-2001 Aaron Holtzman <aholtzma@ess.engr.uvic.ca>
+ *
+ * This file is part of mpeg2dec, a free MPEG-2 video stream decoder.
+ *
+ * mpeg2dec is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * mpeg2dec 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include "config.h"
+
+#include <inttypes.h>
+
+#include "mpeg2_internal.h"
+#include "attributes.h"
+
+/* default intra quant matrix, in zig-zag order */
+static uint8_t default_intra_quantizer_matrix[64] ATTR_ALIGN(16) = {
+    8,
+    16, 16,
+    19, 16, 19,
+    22, 22, 22, 22,
+    22, 22, 26, 24, 26,
+    27, 27, 27, 26, 26, 26,
+    26, 27, 27, 27, 29, 29, 29,
+    34, 34, 34, 29, 29, 29, 27, 27,
+    29, 29, 32, 32, 34, 34, 37,
+    38, 37, 35, 35, 34, 35,
+    38, 38, 40, 40, 40,
+    48, 48, 46, 46,
+    56, 56, 58,
+    69, 69,
+    83
+};
+
+uint8_t scan_norm[64] ATTR_ALIGN(16) =
+{
+    /* Zig-Zag scan pattern */
+     0, 1, 8,16, 9, 2, 3,10,
+    17,24,32,25,18,11, 4, 5,
+    12,19,26,33,40,48,41,34,
+    27,20,13, 6, 7,14,21,28,
+    35,42,49,56,57,50,43,36,
+    29,22,15,23,30,37,44,51,
+    58,59,52,45,38,31,39,46,
+    53,60,61,54,47,55,62,63
+};
+
+uint8_t scan_alt[64] ATTR_ALIGN(16) =
+{
+    /* Alternate scan pattern */
+    0,8,16,24,1,9,2,10,17,25,32,40,48,56,57,49,
+    41,33,26,18,3,11,4,12,19,27,34,42,50,58,35,43,
+    51,59,20,28,5,13,6,14,21,29,36,44,52,60,37,45,
+    53,61,22,30,7,15,23,31,38,46,54,62,39,47,55,63
+};
+
+void header_state_init (picture_t * picture)
+{
+    picture->scan = scan_norm;
+}
+
+int header_process_sequence_header (picture_t * picture, uint8_t * buffer)
+{
+    int width, height;
+    int i;
+
+    if ((buffer[6] & 0x20) != 0x20)
+	return 1;	/* missing marker_bit */
+
+    height = (buffer[0] << 16) | (buffer[1] << 8) | buffer[2];
+
+    width = ((height >> 12) + 15) & ~15;
+    height = ((height & 0xfff) + 15) & ~15;
+
+    if ((width > 768) || (height > 576))
+	return 1;	/* size restrictions for MP@ML or MPEG1 */
+
+    picture->coded_picture_width = width;
+    picture->coded_picture_height = height;
+
+    /* this is not used by the decoder */
+    picture->aspect_ratio_information = buffer[3] >> 4;
+    picture->frame_rate_code = buffer[3] & 15;
+    picture->bitrate = (buffer[4]<<10)|(buffer[5]<<2)|(buffer[6]>>6);
+
+    if (buffer[7] & 2) {
+	for (i = 0; i < 64; i++)
+	    picture->intra_quantizer_matrix[scan_norm[i]] =
+		(buffer[i+7] << 7) | (buffer[i+8] >> 1);
+	buffer += 64;
+    } else {
+	for (i = 0; i < 64; i++)
+	    picture->intra_quantizer_matrix[scan_norm[i]] =
+		default_intra_quantizer_matrix [i];
+    }
+
+    if (buffer[7] & 1) {
+	for (i = 0; i < 64; i++)
+	    picture->non_intra_quantizer_matrix[scan_norm[i]] =
+		buffer[i+8];
+    } else {
+	for (i = 0; i < 64; i++)
+	    picture->non_intra_quantizer_matrix[i] = 16;
+    }
+
+    /* MPEG1 - for testing only */
+    picture->mpeg1 = 1;
+    picture->intra_dc_precision = 0;
+    picture->frame_pred_frame_dct = 1;
+    picture->q_scale_type = 0;
+    picture->concealment_motion_vectors = 0;
+    /* picture->alternate_scan = 0; */
+    picture->picture_structure = FRAME_PICTURE;
+    /* picture->second_field = 0; */
+
+    return 0;
+}
+
+static int header_process_sequence_extension (picture_t * picture,
+					      uint8_t * buffer)
+{
+    /* check chroma format, size extensions, marker bit */
+    if (((buffer[1] & 0x07) != 0x02) || (buffer[2] & 0xe0) ||
+	((buffer[3] & 0x01) != 0x01))
+	return 1;
+
+    /* this is not used by the decoder */
+    picture->progressive_sequence = (buffer[1] >> 3) & 1;
+
+    if (picture->progressive_sequence)
+	picture->coded_picture_height =
+	    (picture->coded_picture_height + 31) & ~31;
+
+    /* MPEG1 - for testing only */
+    picture->mpeg1 = 0;
+
+    return 0;
+}
+
+static int header_process_quant_matrix_extension (picture_t * picture,
+						  uint8_t * buffer)
+{
+    int i;
+
+    if (buffer[0] & 8) {
+	for (i = 0; i < 64; i++)
+	    picture->intra_quantizer_matrix[scan_norm[i]] =
+		(buffer[i] << 5) | (buffer[i+1] >> 3);
+	buffer += 64;
+    }
+
+    if (buffer[0] & 4) {
+	for (i = 0; i < 64; i++)
+	    picture->non_intra_quantizer_matrix[scan_norm[i]] =
+		(buffer[i] << 6) | (buffer[i+1] >> 2);
+    }
+
+    return 0;
+}
+
+static int header_process_picture_coding_extension (picture_t * picture, uint8_t * buffer)
+{
+    /* pre subtract 1 for use later in compute_motion_vector */
+    picture->f_motion.f_code[0] = (buffer[0] & 15) - 1;
+    picture->f_motion.f_code[1] = (buffer[1] >> 4) - 1;
+    picture->b_motion.f_code[0] = (buffer[1] & 15) - 1;
+    picture->b_motion.f_code[1] = (buffer[2] >> 4) - 1;
+
+    picture->intra_dc_precision = (buffer[2] >> 2) & 3;
+    picture->picture_structure = buffer[2] & 3;
+    picture->frame_pred_frame_dct = (buffer[3] >> 6) & 1;
+    picture->concealment_motion_vectors = (buffer[3] >> 5) & 1;
+    picture->q_scale_type = (buffer[3] >> 4) & 1;
+    picture->intra_vlc_format = (buffer[3] >> 3) & 1;
+
+    if (buffer[3] & 4)	/* alternate_scan */
+	picture->scan = scan_alt;
+    else
+	picture->scan = scan_norm;
+
+    /* these are not used by the decoder */
+    picture->top_field_first = buffer[3] >> 7;
+    picture->repeat_first_field = (buffer[3] >> 1) & 1;
+    picture->progressive_frame = buffer[4] >> 7;
+
+    return 0;
+}
+
+int header_process_extension (picture_t * picture, uint8_t * buffer)
+{
+    switch (buffer[0] & 0xf0) {
+    case 0x10:	/* sequence extension */
+	return header_process_sequence_extension (picture, buffer);
+
+    case 0x30:	/* quant matrix extension */
+	return header_process_quant_matrix_extension (picture, buffer);
+
+    case 0x80:	/* picture coding extension */
+	return header_process_picture_coding_extension (picture, buffer);
+    }
+
+    return 0;
+}
+
+int header_process_picture_header (picture_t *picture, uint8_t * buffer)
+{
+    picture->picture_coding_type = (buffer [1] >> 3) & 7;
+
+    /* forward_f_code and backward_f_code - used in mpeg1 only */
+    picture->f_motion.f_code[1] = (buffer[3] >> 2) & 1;
+    picture->f_motion.f_code[0] =
+	(((buffer[3] << 1) | (buffer[4] >> 7)) & 7) - 1;
+    picture->b_motion.f_code[1] = (buffer[4] >> 6) & 1;
+    picture->b_motion.f_code[0] = ((buffer[4] >> 3) & 7) - 1;
+
+    /* move in header_process_picture_header */
+        picture->second_field =
+            (picture->picture_structure != FRAME_PICTURE) &&
+            !(picture->second_field);
+
+    return 0;
+}