[FFmpeg-soc] [soc]: r1723 - in eac3: ac3_parser.c checkout.sh ffmpeg.patch

jbr subversion at mplayerhq.hu
Mon Dec 31 02:08:32 CET 2007


Author: jbr
Date: Mon Dec 31 02:08:31 2007
New Revision: 1723

Log:
add ac3_parser.c to soc svn

Added:
   eac3/ac3_parser.c
Modified:
   eac3/checkout.sh
   eac3/ffmpeg.patch

Added: eac3/ac3_parser.c
==============================================================================
--- (empty file)
+++ eac3/ac3_parser.c	Mon Dec 31 02:08:31 2007
@@ -0,0 +1,177 @@
+/*
+ * AC3 parser
+ * Copyright (c) 2003 Fabrice Bellard.
+ * Copyright (c) 2003 Michael Niedermayer.
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "parser.h"
+#include "ac3_parser.h"
+#include "aac_ac3_parser.h"
+#include "bitstream.h"
+
+
+#define AC3_HEADER_SIZE 7
+
+
+static const uint8_t eac3_blocks[4] = {
+    1, 2, 3, 6
+};
+
+
+int ff_ac3_parse_header(const uint8_t buf[7], AC3HeaderInfo *hdr)
+{
+    GetBitContext gbc;
+
+    memset(hdr, 0, sizeof(*hdr));
+
+    init_get_bits(&gbc, buf, 54);
+
+    hdr->sync_word = get_bits(&gbc, 16);
+    if(hdr->sync_word != 0x0B77)
+        return AC3_PARSE_ERROR_SYNC;
+
+    /* read ahead to bsid to make sure this is AC-3, not E-AC-3 */
+    hdr->bitstream_id = show_bits_long(&gbc, 29) & 0x1F;
+    if(hdr->bitstream_id > 10)
+        return AC3_PARSE_ERROR_BSID;
+
+    hdr->crc1 = get_bits(&gbc, 16);
+    hdr->sr_code = get_bits(&gbc, 2);
+    if(hdr->sr_code == 3)
+        return AC3_PARSE_ERROR_SAMPLE_RATE;
+
+    hdr->frame_size_code = get_bits(&gbc, 6);
+    if(hdr->frame_size_code > 37)
+        return AC3_PARSE_ERROR_FRAME_SIZE;
+
+    skip_bits(&gbc, 5); // skip bsid, already got it
+
+    hdr->bitstream_mode = get_bits(&gbc, 3);
+    hdr->channel_mode = get_bits(&gbc, 3);
+    if((hdr->channel_mode & 1) && hdr->channel_mode != AC3_CHMODE_MONO) {
+        skip_bits(&gbc, 2); // skip center mix level
+    }
+    if(hdr->channel_mode & 4) {
+        skip_bits(&gbc, 2); // skip surround mix level
+    }
+    if(hdr->channel_mode == AC3_CHMODE_STEREO) {
+        skip_bits(&gbc, 2); // skip dolby surround mode
+    }
+    hdr->lfe_on = get_bits1(&gbc);
+
+    hdr->sr_shift = FFMAX(hdr->bitstream_id, 8) - 8;
+    hdr->sample_rate = ff_ac3_sample_rate_tab[hdr->sr_code] >> hdr->sr_shift;
+    hdr->bit_rate = (ff_ac3_bitrate_tab[hdr->frame_size_code>>1] * 1000) >> hdr->sr_shift;
+    hdr->channels = ff_ac3_channels_tab[hdr->channel_mode] + hdr->lfe_on;
+    hdr->frame_size = ff_ac3_frame_size_tab[hdr->frame_size_code][hdr->sr_code] * 2;
+
+    return 0;
+}
+
+static int ac3_sync(AVCodecContext *avctx, const uint8_t *buf, int *channels, int *sample_rate,
+                    int *bit_rate, int *samples)
+{
+    int err;
+    unsigned int sr_code, channel_mode, bitstream_id, lfe_on;
+    unsigned int stream_type, substream_id, frame_size, sr_code2, num_blocks_code;
+    GetBitContext bits;
+    AC3HeaderInfo hdr;
+
+    err = ff_ac3_parse_header(buf, &hdr);
+
+    if(err < 0 && err != -2)
+        return 0;
+
+    bitstream_id = hdr.bitstream_id;
+    if(bitstream_id <= 10) {             /* Normal AC-3 */
+        if(avctx->codec_id == CODEC_ID_EAC3)
+            avctx->codec_id = CODEC_ID_AC3;
+        *sample_rate = hdr.sample_rate;
+        *bit_rate = hdr.bit_rate;
+        *channels = hdr.channels;
+        *samples = AC3_FRAME_SIZE;
+        return hdr.frame_size;
+    } else if (bitstream_id > 10 && bitstream_id <= 16) { /* Enhanced AC-3 */
+        if(avctx->codec_id == CODEC_ID_AC3)
+            avctx->codec_id = CODEC_ID_EAC3;
+        init_get_bits(&bits, &buf[2], (AC3_HEADER_SIZE-2) * 8);
+        stream_type = get_bits(&bits, 2);
+        substream_id = get_bits(&bits, 3);
+
+        if (stream_type != 0 || substream_id != 0)
+            return 0;   /* Currently don't support additional streams */
+
+        frame_size = get_bits(&bits, 11) + 1;
+        if(frame_size*2 < AC3_HEADER_SIZE)
+            return 0;
+
+        sr_code = get_bits(&bits, 2);
+        if (sr_code == 3) {
+            sr_code2 = get_bits(&bits, 2);
+            num_blocks_code = 3;
+
+            if(sr_code2 == 3)
+                return 0;
+
+            *sample_rate = ff_ac3_sample_rate_tab[sr_code2] / 2;
+        } else {
+            num_blocks_code = get_bits(&bits, 2);
+
+            *sample_rate = ff_ac3_sample_rate_tab[sr_code];
+        }
+
+        channel_mode = get_bits(&bits, 3);
+        lfe_on = get_bits1(&bits);
+
+        *samples = eac3_blocks[num_blocks_code] * 256;
+        *bit_rate = frame_size * (*sample_rate) * 16 / (*samples);
+        *channels = ff_ac3_channels_tab[channel_mode] + lfe_on;
+
+        return frame_size * 2;
+    }
+
+    /* Unsupported bitstream version */
+    return 0;
+}
+
+static int ac3_parse_init(AVCodecParserContext *s1)
+{
+    AACAC3ParseContext *s = s1->priv_data;
+    s->inbuf_ptr = s->inbuf;
+    s->header_size = AC3_HEADER_SIZE;
+    s->sync = ac3_sync;
+    return 0;
+}
+
+
+AVCodecParser ac3_parser = {
+    { CODEC_ID_AC3 },
+    sizeof(AACAC3ParseContext),
+    ac3_parse_init,
+    ff_aac_ac3_parse,
+    NULL,
+};
+
+AVCodecParser eac3_parser = {
+    { CODEC_ID_EAC3 },
+    sizeof(AACAC3ParseContext),
+    ac3_parse_init,
+    ff_aac_ac3_parse,
+    NULL,
+};

Modified: eac3/checkout.sh
==============================================================================
--- eac3/checkout.sh	(original)
+++ eac3/checkout.sh	Mon Dec 31 02:08:31 2007
@@ -1,7 +1,7 @@
-FILES="ac3.c ac3.h ac3tab.c ac3tab.h eac3dec.c ac3dec.c ac3dec.h"
+FILES="ac3.c ac3.h ac3tab.c ac3tab.h eac3dec.c ac3dec.c ac3dec.h ac3_parser.c"
 
 echo "checking out ffmpeg svn"
-for i in $FILES ac3_parser.c Makefile aac_ac3_parser.c aac_ac3_parser.h aac_parser.c allcodecs.c avcodec.h ../libavformat/allformats.h ../libavformat/raw.c allcodecs.h ac3enc.c ../ffmpeg.c; do
+for i in $FILES Makefile aac_ac3_parser.c aac_ac3_parser.h aac_parser.c allcodecs.c avcodec.h ../libavformat/allformats.h ../libavformat/raw.c allcodecs.h ac3enc.c ../ffmpeg.c; do
     rm -f ffmpeg/libavcodec/$i
 done
 svn checkout svn://svn.mplayerhq.hu/ffmpeg/trunk/ ffmpeg -r 11360

Modified: eac3/ffmpeg.patch
==============================================================================
--- eac3/ffmpeg.patch	(original)
+++ eac3/ffmpeg.patch	Mon Dec 31 02:08:31 2007
@@ -86,65 +86,6 @@ Index: libavcodec/allcodecs.c
      REGISTER_PARSER  (H261, h261);
      REGISTER_PARSER  (H263, h263);
      REGISTER_PARSER  (H264, h264);
-Index: libavcodec/ac3_parser.c
-===================================================================
---- libavcodec/ac3_parser.c	(revision 11360)
-+++ libavcodec/ac3_parser.c	(working copy)
-@@ -65,13 +65,13 @@
-     hdr->bitstream_mode = get_bits(&gbc, 3);
-     hdr->channel_mode = get_bits(&gbc, 3);
-     if((hdr->channel_mode & 1) && hdr->channel_mode != AC3_CHMODE_MONO) {
--        hdr->center_mix_level = get_bits(&gbc, 2);
-+        skip_bits(&gbc, 2); // skip center mix level
-     }
-     if(hdr->channel_mode & 4) {
--        hdr->surround_mix_level = get_bits(&gbc, 2);
-+        skip_bits(&gbc, 2); // skip surround mix level
-     }
-     if(hdr->channel_mode == AC3_CHMODE_STEREO) {
--        hdr->dolby_surround_mode = get_bits(&gbc, 2);
-+        skip_bits(&gbc, 2); // skip dolby surround mode
-     }
-     hdr->lfe_on = get_bits1(&gbc);
- 
-@@ -84,7 +84,7 @@
-     return 0;
- }
- 
--static int ac3_sync(const uint8_t *buf, int *channels, int *sample_rate,
-+static int ac3_sync(AVCodecContext *avctx, const uint8_t *buf, int *channels, int *sample_rate,
-                     int *bit_rate, int *samples)
- {
-     int err;
-@@ -100,12 +100,16 @@
- 
-     bitstream_id = hdr.bitstream_id;
-     if(bitstream_id <= 10) {             /* Normal AC-3 */
-+        if(avctx->codec_id == CODEC_ID_EAC3)
-+            avctx->codec_id = CODEC_ID_AC3;
-         *sample_rate = hdr.sample_rate;
-         *bit_rate = hdr.bit_rate;
-         *channels = hdr.channels;
-         *samples = AC3_FRAME_SIZE;
-         return hdr.frame_size;
-     } else if (bitstream_id > 10 && bitstream_id <= 16) { /* Enhanced AC-3 */
-+        if(avctx->codec_id == CODEC_ID_AC3)
-+            avctx->codec_id = CODEC_ID_EAC3;
-         init_get_bits(&bits, &buf[2], (AC3_HEADER_SIZE-2) * 8);
-         stream_type = get_bits(&bits, 2);
-         substream_id = get_bits(&bits, 3);
-@@ -163,3 +167,11 @@
-     ff_aac_ac3_parse,
-     NULL,
- };
-+
-+AVCodecParser eac3_parser = {
-+    { CODEC_ID_EAC3 },
-+    sizeof(AACAC3ParseContext),
-+    ac3_parse_init,
-+    ff_aac_ac3_parse,
-+    NULL,
-+};
 Index: libavcodec/avcodec.h
 ===================================================================
 --- libavcodec/avcodec.h	(revision 11360)



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