[FFmpeg-cvslog] dca_parser: parse the sample rate and frame durations

Justin Ruggles git at videolan.org
Tue Mar 6 06:16:02 CET 2012


ffmpeg | branch: master | Justin Ruggles <justin.ruggles at gmail.com> | Mon Feb 27 13:58:01 2012 -0500| [11ac796f7ab2738eff19ea18847355363c8cc797] | committer: Justin Ruggles

dca_parser: parse the sample rate and frame durations

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=11ac796f7ab2738eff19ea18847355363c8cc797
---

 libavcodec/Makefile     |    3 +-
 libavcodec/dca.c        |   47 ++--------------------------
 libavcodec/dca_parser.c |   80 ++++++++++++++++++++++++++++++++++++++++++++++-
 libavcodec/dca_parser.h |   36 +++++++++++++++++++++
 4 files changed, 120 insertions(+), 46 deletions(-)

diff --git a/libavcodec/Makefile b/libavcodec/Makefile
index e456790..ba83d35 100644
--- a/libavcodec/Makefile
+++ b/libavcodec/Makefile
@@ -109,7 +109,8 @@ OBJS-$(CONFIG_CLJR_ENCODER)            += cljr.o
 OBJS-$(CONFIG_COOK_DECODER)            += cook.o
 OBJS-$(CONFIG_CSCD_DECODER)            += cscd.o
 OBJS-$(CONFIG_CYUV_DECODER)            += cyuv.o
-OBJS-$(CONFIG_DCA_DECODER)             += dca.o synth_filter.o dcadsp.o
+OBJS-$(CONFIG_DCA_DECODER)             += dca.o synth_filter.o dcadsp.o \
+                                          dca_parser.o
 OBJS-$(CONFIG_DFA_DECODER)             += dfa.o
 OBJS-$(CONFIG_DNXHD_DECODER)           += dnxhddec.o dnxhddata.o
 OBJS-$(CONFIG_DNXHD_ENCODER)           += dnxhdenc.o dnxhddata.o       \
diff --git a/libavcodec/dca.c b/libavcodec/dca.c
index 3f62c1e..71c1800 100644
--- a/libavcodec/dca.c
+++ b/libavcodec/dca.c
@@ -38,6 +38,7 @@
 #include "dcadata.h"
 #include "dcahuff.h"
 #include "dca.h"
+#include "dca_parser.h"
 #include "synth_filter.h"
 #include "dcadsp.h"
 #include "fmtconvert.h"
@@ -1361,47 +1362,6 @@ static int dca_decode_block(DCAContext *s, int base_channel, int block_index)
 }
 
 /**
- * Convert bitstream to one representation based on sync marker
- */
-static int dca_convert_bitstream(const uint8_t *src, int src_size, uint8_t *dst,
-                                 int max_size)
-{
-    uint32_t mrk;
-    int i, tmp;
-    const uint16_t *ssrc = (const uint16_t *) src;
-    uint16_t *sdst = (uint16_t *) dst;
-    PutBitContext pb;
-
-    if ((unsigned) src_size > (unsigned) max_size) {
-//        av_log(NULL, AV_LOG_ERROR, "Input frame size larger than DCA_MAX_FRAME_SIZE!\n");
-//        return -1;
-        src_size = max_size;
-    }
-
-    mrk = AV_RB32(src);
-    switch (mrk) {
-    case DCA_MARKER_RAW_BE:
-        memcpy(dst, src, src_size);
-        return src_size;
-    case DCA_MARKER_RAW_LE:
-        for (i = 0; i < (src_size + 1) >> 1; i++)
-            *sdst++ = av_bswap16(*ssrc++);
-        return src_size;
-    case DCA_MARKER_14B_BE:
-    case DCA_MARKER_14B_LE:
-        init_put_bits(&pb, dst, max_size);
-        for (i = 0; i < (src_size + 1) >> 1; i++, src += 2) {
-            tmp = ((mrk == DCA_MARKER_14B_BE) ? AV_RB16(src) : AV_RL16(src)) & 0x3FFF;
-            put_bits(&pb, 14, tmp);
-        }
-        flush_put_bits(&pb);
-        return (put_bits_count(&pb) + 7) >> 3;
-    default:
-        return AVERROR_INVALIDDATA;
-    }
-}
-
-/**
  * Return the number of channels in an ExSS speaker mask (HD)
  */
 static int dca_exss_mask2count(int mask)
@@ -1688,8 +1648,8 @@ static int dca_decode_frame(AVCodecContext *avctx, void *data,
 
     s->xch_present = 0;
 
-    s->dca_buffer_size = dca_convert_bitstream(buf, buf_size, s->dca_buffer,
-                                               DCA_MAX_FRAME_SIZE + DCA_MAX_EXSS_HEADER_SIZE);
+    s->dca_buffer_size = ff_dca_convert_bitstream(buf, buf_size, s->dca_buffer,
+                                                  DCA_MAX_FRAME_SIZE + DCA_MAX_EXSS_HEADER_SIZE);
     if (s->dca_buffer_size == AVERROR_INVALIDDATA) {
         av_log(avctx, AV_LOG_ERROR, "Not a valid DCA frame\n");
         return AVERROR_INVALIDDATA;
@@ -1703,7 +1663,6 @@ static int dca_decode_frame(AVCodecContext *avctx, void *data,
     //set AVCodec values with parsed data
     avctx->sample_rate = s->sample_rate;
     avctx->bit_rate    = s->bit_rate;
-    avctx->frame_size  = s->sample_blocks * 32;
 
     s->profile = FF_PROFILE_DTS;
 
diff --git a/libavcodec/dca_parser.c b/libavcodec/dca_parser.c
index 136cc45..e7b2ce4 100644
--- a/libavcodec/dca_parser.c
+++ b/libavcodec/dca_parser.c
@@ -24,6 +24,10 @@
 
 #include "parser.h"
 #include "dca.h"
+#include "dcadata.h"
+#include "dca_parser.h"
+#include "get_bits.h"
+#include "put_bits.h"
 
 typedef struct DCAParseContext {
     ParseContext pc;
@@ -100,6 +104,71 @@ static av_cold int dca_parse_init(AVCodecParserContext * s)
     return 0;
 }
 
+int ff_dca_convert_bitstream(const uint8_t *src, int src_size, uint8_t *dst,
+                             int max_size)
+{
+    uint32_t mrk;
+    int i, tmp;
+    const uint16_t *ssrc = (const uint16_t *) src;
+    uint16_t *sdst = (uint16_t *) dst;
+    PutBitContext pb;
+
+    if ((unsigned) src_size > (unsigned) max_size)
+        src_size = max_size;
+
+    mrk = AV_RB32(src);
+    switch (mrk) {
+    case DCA_MARKER_RAW_BE:
+        memcpy(dst, src, src_size);
+        return src_size;
+    case DCA_MARKER_RAW_LE:
+        for (i = 0; i < (src_size + 1) >> 1; i++)
+            *sdst++ = av_bswap16(*ssrc++);
+        return src_size;
+    case DCA_MARKER_14B_BE:
+    case DCA_MARKER_14B_LE:
+        init_put_bits(&pb, dst, max_size);
+        for (i = 0; i < (src_size + 1) >> 1; i++, src += 2) {
+            tmp = ((mrk == DCA_MARKER_14B_BE) ? AV_RB16(src) : AV_RL16(src)) & 0x3FFF;
+            put_bits(&pb, 14, tmp);
+        }
+        flush_put_bits(&pb);
+        return (put_bits_count(&pb) + 7) >> 3;
+    default:
+        return AVERROR_INVALIDDATA;
+    }
+}
+
+static int dca_parse_params(const uint8_t *buf, int buf_size, int *duration,
+                            int *sample_rate)
+{
+    GetBitContext gb;
+    uint8_t hdr[12 + FF_INPUT_BUFFER_PADDING_SIZE] = { 0 };
+    int ret, sample_blocks, sr_code;
+
+    if (buf_size < 12)
+        return AVERROR_INVALIDDATA;
+
+    if ((ret = ff_dca_convert_bitstream(buf, 12, hdr, 12)) < 0)
+        return ret;
+
+    init_get_bits(&gb, hdr, 96);
+
+    skip_bits_long(&gb, 39);
+    sample_blocks = get_bits(&gb, 7) + 1;
+    if (sample_blocks < 8)
+        return AVERROR_INVALIDDATA;
+    *duration = 256 * (sample_blocks / 8);
+
+    skip_bits(&gb, 20);
+    sr_code = get_bits(&gb, 4);
+    *sample_rate = dca_sample_rates[sr_code];
+    if (*sample_rate == 0)
+        return AVERROR_INVALIDDATA;
+
+    return 0;
+}
+
 static int dca_parse(AVCodecParserContext * s,
                      AVCodecContext * avctx,
                      const uint8_t ** poutbuf, int *poutbuf_size,
@@ -107,7 +176,7 @@ static int dca_parse(AVCodecParserContext * s,
 {
     DCAParseContext *pc1 = s->priv_data;
     ParseContext *pc = &pc1->pc;
-    int next;
+    int next, duration, sample_rate;
 
     if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) {
         next = buf_size;
@@ -120,6 +189,15 @@ static int dca_parse(AVCodecParserContext * s,
             return buf_size;
         }
     }
+
+    /* read the duration and sample rate from the frame header */
+    if (!dca_parse_params(buf, buf_size, &duration, &sample_rate)) {
+        s->duration = duration;
+        if (!avctx->sample_rate)
+            avctx->sample_rate = sample_rate;
+    } else
+        s->duration = 0;
+
     *poutbuf = buf;
     *poutbuf_size = buf_size;
     return next;
diff --git a/libavcodec/dca_parser.h b/libavcodec/dca_parser.h
new file mode 100644
index 0000000..f480eab
--- /dev/null
+++ b/libavcodec/dca_parser.h
@@ -0,0 +1,36 @@
+/*
+ * DCA parser
+ * Copyright (C) 2004 Gildas Bazin
+ * Copyright (C) 2004 Benjamin Zores
+ * Copyright (C) 2006 Benjamin Larsson
+ * Copyright (C) 2007 Konstantin Shishkov
+ *
+ * This file is part of Libav.
+ *
+ * Libav 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.
+ *
+ * Libav 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 Libav; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef AVCODEC_DCA_PARSER_H
+#define AVCODEC_DCA_PARSER_H
+
+#include <stdint.h>
+
+/**
+ * Convert bitstream to one representation based on sync marker
+ */
+int ff_dca_convert_bitstream(const uint8_t *src, int src_size, uint8_t *dst,
+                             int max_size);
+
+#endif /* AVCODEC_DCA_PARSER_H */



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