diff --git a/libavcodec/Makefile b/libavcodec/Makefile
index bc4d7dab27..8c878c3699 100644
--- a/libavcodec/Makefile
+++ b/libavcodec/Makefile
@@ -1,7 +1,8 @@
 NAME = avcodec
 DESC = FFmpeg codec library
 
-HEADERS = avcodec.h                                                     \
+HEADERS = ac3_parser.h                                                  \
+          avcodec.h                                                     \
           avdct.h                                                       \
           avfft.h                                                       \
           d3d11va.h                                                     \
@@ -18,7 +19,8 @@ HEADERS = avcodec.h                                                     \
           vorbis_parser.h                                               \
           xvmc.h                                                        \
 
-OBJS = allcodecs.o                                                      \
+OBJS = ac3_parser.o                                                     \
+       allcodecs.o                                                      \
        avdct.o                                                          \
        avpacket.o                                                       \
        avpicture.o                                                      \
@@ -955,8 +957,7 @@ OBJS-$(CONFIG_LIBZVBI_TELETEXT_DECODER)   += libzvbi-teletextdec.o ass.o
 OBJS-$(CONFIG_AAC_LATM_PARSER)         += latm_parser.o
 OBJS-$(CONFIG_AAC_PARSER)              += aac_parser.o aac_ac3_parser.o \
                                           aacadtsdec.o mpeg4audio.o
-OBJS-$(CONFIG_AC3_PARSER)              += ac3_parser.o ac3tab.o \
-                                          aac_ac3_parser.o
+OBJS-$(CONFIG_AC3_PARSER)              += ac3tab.o aac_ac3_parser.o
 OBJS-$(CONFIG_ADX_PARSER)              += adx_parser.o adx.o
 OBJS-$(CONFIG_BMP_PARSER)              += bmp_parser.o
 OBJS-$(CONFIG_CAVSVIDEO_PARSER)        += cavs_parser.o
diff --git a/libavcodec/ac3_parser.c b/libavcodec/ac3_parser.c
index 83dd90ff67..1015245a90 100644
--- a/libavcodec/ac3_parser.c
+++ b/libavcodec/ac3_parser.c
@@ -20,15 +20,19 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
+#include "config.h"
+
 #include "libavutil/channel_layout.h"
 #include "parser.h"
 #include "ac3_parser.h"
+#include "ac3_parser_internal.h"
 #include "aac_ac3_parser.h"
 #include "get_bits.h"
 
 
 #define AC3_HEADER_SIZE 7
 
+#if CONFIG_AC3_PARSER
 
 static const uint8_t eac3_blocks[4] = {
     1, 2, 3, 6
@@ -47,16 +51,9 @@ static const uint8_t center_levels[4] = { 4, 5, 6, 5 };
 static const uint8_t surround_levels[4] = { 4, 6, 7, 6 };
 
 
-int avpriv_ac3_parse_header(GetBitContext *gbc, AC3HeaderInfo **phdr)
+int ff_ac3_parse_header(GetBitContext *gbc, AC3HeaderInfo *hdr)
 {
     int frame_size_code;
-    AC3HeaderInfo *hdr;
-
-    if (!*phdr)
-        *phdr = av_mallocz(sizeof(AC3HeaderInfo));
-    if (!*phdr)
-        return AVERROR(ENOMEM);
-    hdr = *phdr;
 
     memset(hdr, 0, sizeof(*hdr));
 
@@ -151,6 +148,46 @@ int avpriv_ac3_parse_header(GetBitContext *gbc, AC3HeaderInfo **phdr)
     return 0;
 }
 
+// TODO: Better way to pass AC3HeaderInfo fields to mov muxer.
+int avpriv_ac3_parse_header(AC3HeaderInfo **phdr, const uint8_t *buf,
+                            size_t size)
+{
+    GetBitContext gb;
+    AC3HeaderInfo *hdr;
+    int err;
+
+    if (!*phdr)
+        *phdr = av_mallocz(sizeof(AC3HeaderInfo));
+    if (!*phdr)
+        return AVERROR(ENOMEM);
+    hdr = *phdr;
+
+    init_get_bits8(&gb, buf, size);
+    err = ff_ac3_parse_header(&gb, hdr);
+    if (err < 0)
+        return AVERROR_INVALIDDATA;
+
+    return get_bits_count(&gb);
+}
+
+int av_ac3_parse_header(const uint8_t *buf, size_t size,
+                        uint8_t *bitstream_id, uint16_t *frame_size)
+{
+    GetBitContext gb;
+    AC3HeaderInfo hdr;
+    int err;
+
+    init_get_bits8(&gb, buf, size);
+    err = ff_ac3_parse_header(&gb, &hdr);
+    if (err < 0)
+        return AVERROR_INVALIDDATA;
+
+    *bitstream_id = hdr.bitstream_id;
+    *frame_size   = hdr.frame_size;
+
+    return 0;
+}
+
 static int ac3_sync(uint64_t state, AACAC3ParseContext *hdr_info,
         int *need_next_header, int *new_frame_start)
 {
@@ -159,11 +196,11 @@ static int ac3_sync(uint64_t state, AACAC3ParseContext *hdr_info,
         uint64_t u64;
         uint8_t  u8[8 + AV_INPUT_BUFFER_PADDING_SIZE];
     } tmp = { av_be2ne64(state) };
-    AC3HeaderInfo hdr, *phdr = &hdr;
+    AC3HeaderInfo hdr;
     GetBitContext gbc;
 
     init_get_bits(&gbc, tmp.u8+8-AC3_HEADER_SIZE, 54);
-    err = avpriv_ac3_parse_header(&gbc, &phdr);
+    err = ff_ac3_parse_header(&gbc, &hdr);
 
     if(err < 0)
         return 0;
@@ -202,3 +239,18 @@ AVCodecParser ff_ac3_parser = {
     .parser_parse   = ff_aac_ac3_parse,
     .parser_close   = ff_parse_close,
 };
+
+#else
+
+int avpriv_ac3_parse_header(AC3HeaderInfo **phdr, const uint8_t *buf,
+                            size_t size)
+{
+    return AVERROR(ENOSYS);
+}
+
+int av_ac3_parse_header(const uint8_t *buf, size_t size,
+                        uint8_t *bitstream_id, uint16_t *frame_size)
+{
+    return AVERROR(ENOSYS);
+}
+#endif
diff --git a/libavcodec/ac3_parser.h b/libavcodec/ac3_parser.h
index dc5d035e11..ff8cc4cf09 100644
--- a/libavcodec/ac3_parser.h
+++ b/libavcodec/ac3_parser.h
@@ -23,20 +23,14 @@
 #ifndef AVCODEC_AC3_PARSER_H
 #define AVCODEC_AC3_PARSER_H
 
-#include "ac3.h"
-#include "get_bits.h"
+#include <stddef.h>
+#include <stdint.h>
 
 /**
- * Parse AC-3 frame header.
- * Parse the header up to the lfeon element, which is the first 52 or 54 bits
- * depending on the audio coding mode.
- * @param[in]  gbc BitContext containing the first 54 bits of the frame.
- * @param[out] hdr Pointer to Pointer to struct where header info is written.
- *                 will be allocated if NULL
- * @return Returns 0 on success, -1 if there is a sync word mismatch,
- * -2 if the bsid (version) element is invalid, -3 if the fscod (sample rate)
- * element is invalid, or -4 if the frmsizecod (bit rate) element is invalid.
+ * Extract the bitstream ID and the frame size from AC-3 data.
  */
-int avpriv_ac3_parse_header(GetBitContext *gbc, AC3HeaderInfo **hdr);
+int av_ac3_parse_header(const uint8_t *buf, size_t size,
+                        uint8_t *bitstream_id, uint16_t *frame_size);
+
 
 #endif /* AVCODEC_AC3_PARSER_H */
diff --git a/libavcodec/ac3_parser_internal.h b/libavcodec/ac3_parser_internal.h
new file mode 100644
index 0000000000..3648802a73
--- /dev/null
+++ b/libavcodec/ac3_parser_internal.h
@@ -0,0 +1,42 @@
+/*
+ * AC-3 parser internal code
+ *
+ * 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
+ */
+
+#ifndef AVCODEC_AC3_PARSER_INTERNAL_H
+#define AVCODEC_AC3_PARSER_INTERNAL_H
+
+#include "ac3.h"
+#include "get_bits.h"
+
+/**
+ * Parse AC-3 frame header.
+ * Parse the header up to the lfeon element, which is the first 52 or 54 bits
+ * depending on the audio coding mode.
+ * @param[in]  gbc BitContext containing the first 54 bits of the frame.
+ * @param[out] hdr Pointer to struct where header info is written.
+ * @return Returns 0 on success, -1 if there is a sync word mismatch,
+ * -2 if the bsid (version) element is invalid, -3 if the fscod (sample rate)
+ * element is invalid, or -4 if the frmsizecod (bit rate) element is invalid.
+ */
+int ff_ac3_parse_header(GetBitContext *gbc, AC3HeaderInfo *hdr);
+
+int avpriv_ac3_parse_header(AC3HeaderInfo **hdr, const uint8_t *buf,
+                            size_t size);
+
+#endif /* AVCODEC_AC3_PARSER_INTERNAL_H */
diff --git a/libavcodec/ac3dec.c b/libavcodec/ac3dec.c
index c393076aec..244a18323f 100644
--- a/libavcodec/ac3dec.c
+++ b/libavcodec/ac3dec.c
@@ -36,7 +36,7 @@
 #include "bswapdsp.h"
 #include "internal.h"
 #include "aac_ac3_parser.h"
-#include "ac3_parser.h"
+#include "ac3_parser_internal.h"
 #include "ac3dec.h"
 #include "ac3dec_data.h"
 #include "kbdwin.h"
@@ -297,10 +297,10 @@ static int ac3_parse_header(AC3DecodeContext *s)
  */
 static int parse_frame_header(AC3DecodeContext *s)
 {
-    AC3HeaderInfo hdr, *phdr=&hdr;
+    AC3HeaderInfo hdr;
     int err;
 
-    err = avpriv_ac3_parse_header(&s->gbc, &phdr);
+    err = ff_ac3_parse_header(&s->gbc, &hdr);
     if (err)
         return err;
 
diff --git a/libavcodec/audiotoolboxdec.c b/libavcodec/audiotoolboxdec.c
index 607d3ba4d4..a149949aba 100644
--- a/libavcodec/audiotoolboxdec.c
+++ b/libavcodec/audiotoolboxdec.c
@@ -350,10 +350,10 @@ static av_cold int ffat_create_decoder(AVCodecContext *avctx, AVPacket *pkt)
     } else if (pkt && pkt->size >= 7 &&
                (avctx->codec_id == AV_CODEC_ID_AC3 ||
                 avctx->codec_id == AV_CODEC_ID_EAC3)) {
-        AC3HeaderInfo hdr, *phdr = &hdr;
+        AC3HeaderInfo hdr;
         GetBitContext gbc;
         init_get_bits(&gbc, pkt->data, pkt->size);
-        if (avpriv_ac3_parse_header(&gbc, &phdr) < 0)
+        if (ff_ac3_parse_header(&gbc, &hdr) < 0)
             return AVERROR_INVALIDDATA;
         in_format.mSampleRate = hdr.sample_rate;
         in_format.mChannelsPerFrame = hdr.channels;
diff --git a/libavcodec/eac3dec.c b/libavcodec/eac3dec.c
index c971879b2d..6f6309f179 100644
--- a/libavcodec/eac3dec.c
+++ b/libavcodec/eac3dec.c
@@ -48,7 +48,6 @@
 #include "internal.h"
 #include "aac_ac3_parser.h"
 #include "ac3.h"
-#include "ac3_parser.h"
 #include "ac3dec.h"
 #include "ac3dec_data.h"
 #include "eac3_data.h"
diff --git a/libavformat/ac3dec.c b/libavformat/ac3dec.c
index e85b0ac7c9..8ea73824a6 100644
--- a/libavformat/ac3dec.c
+++ b/libavformat/ac3dec.c
@@ -19,6 +19,7 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
+#include "libavutil/avassert.h"
 #include "libavutil/crc.h"
 #include "libavcodec/ac3_parser.h"
 #include "avformat.h"
@@ -28,8 +29,6 @@ static int ac3_eac3_probe(AVProbeData *p, enum AVCodecID expected_codec_id)
 {
     int max_frames, first_frames = 0, frames;
     const uint8_t *buf, *buf2, *end;
-    AC3HeaderInfo *phdr = NULL;
-    GetBitContext gbc;
     enum AVCodecID codec_id = AV_CODEC_ID_AC3;
 
     max_frames = 0;
@@ -44,7 +43,10 @@ static int ac3_eac3_probe(AVProbeData *p, enum AVCodecID expected_codec_id)
 
         for(frames = 0; buf2 < end; frames++) {
             uint8_t buf3[4096];
-            int i;
+            uint8_t bitstream_id;
+            uint16_t frame_size;
+            int i, ret;
+
             if(!memcmp(buf2, "\x1\x10\0\0\0\0\0\0", 8))
                 buf2+=16;
             if (buf[0] == 0x77 && buf[1] == 0x0B) {
@@ -52,31 +54,35 @@ static int ac3_eac3_probe(AVProbeData *p, enum AVCodecID expected_codec_id)
                     buf3[i  ] = buf2[i+1];
                     buf3[i+1] = buf2[i  ];
                 }
-                init_get_bits(&gbc, buf3, 54);
+                ret = av_ac3_parse_header(buf3, 8, &bitstream_id,
+                                          &frame_size);
             }else
-                init_get_bits(&gbc, buf2, 54);
-            if(avpriv_ac3_parse_header(&gbc, &phdr) < 0)
+                ret = av_ac3_parse_header(buf2, end - buf2, &bitstream_id,
+                                          &frame_size);
+            if (ret < 0)
                 break;
-            if(buf2 + phdr->frame_size > end)
+            if(buf2 + frame_size > end)
                 break;
             if (buf[0] == 0x77 && buf[1] == 0x0B) {
-                av_assert0(phdr->frame_size <= sizeof(buf3));
-                for(i=8; i<phdr->frame_size; i+=2) {
+                av_assert0(frame_size <= sizeof(buf3));
+                for(i = 8; i < frame_size; i += 2) {
                     buf3[i  ] = buf2[i+1];
                     buf3[i+1] = buf2[i  ];
                 }
+                if (av_crc(av_crc_get_table(AV_CRC_16_ANSI), 0, buf3 + 2, frame_size - 2))
+                    break;
+            } else {
+                if (av_crc(av_crc_get_table(AV_CRC_16_ANSI), 0, buf2 + 2, frame_size - 2))
+                    break;
             }
-            if(av_crc(av_crc_get_table(AV_CRC_16_ANSI), 0, gbc.buffer + 2, phdr->frame_size - 2))
-                break;
-            if (phdr->bitstream_id > 10)
+            if (bitstream_id > 10)
                 codec_id = AV_CODEC_ID_EAC3;
-            buf2 += phdr->frame_size;
+            buf2 += frame_size;
         }
         max_frames = FFMAX(max_frames, frames);
         if(buf == p->buf)
             first_frames = frames;
     }
-    av_freep(&phdr);
     if(codec_id != expected_codec_id) return 0;
     // keep this in sync with mp3 probe, both need to avoid
     // issues with MPEG-files!
diff --git a/libavformat/movenc.c b/libavformat/movenc.c
index 2838286141..a34987a7dc 100644
--- a/libavformat/movenc.c
+++ b/libavformat/movenc.c
@@ -31,7 +31,7 @@
 #include "avio.h"
 #include "isom.h"
 #include "avc.h"
-#include "libavcodec/ac3_parser.h"
+#include "libavcodec/ac3_parser_internal.h"
 #include "libavcodec/dnxhddata.h"
 #include "libavcodec/flac.h"
 #include "libavcodec/get_bits.h"
@@ -345,7 +345,6 @@ struct eac3_info {
 #if CONFIG_AC3_PARSER
 static int handle_eac3(MOVMuxContext *mov, AVPacket *pkt, MOVTrack *track)
 {
-    GetBitContext gbc;
     AC3HeaderInfo tmp, *hdr = &tmp;
     struct eac3_info *info;
     int num_blocks;
@@ -354,8 +353,7 @@ static int handle_eac3(MOVMuxContext *mov, AVPacket *pkt, MOVTrack *track)
         return AVERROR(ENOMEM);
     info = track->eac3_priv;
 
-    init_get_bits(&gbc, pkt->data, pkt->size * 8);
-    if (avpriv_ac3_parse_header(&gbc, &hdr) < 0) {
+    if (avpriv_ac3_parse_header(&hdr, pkt->data, pkt->size) < 0) {
         /* drop the packets until we see a good one */
         if (!track->entry) {
             av_log(mov, AV_LOG_WARNING, "Dropping invalid packet from start of the stream\n");
@@ -403,16 +401,18 @@ static int handle_eac3(MOVMuxContext *mov, AVPacket *pkt, MOVTrack *track)
             int parent = hdr->substreamid;
 
             while (cumul_size != pkt->size) {
-                int i;
-                init_get_bits(&gbc, pkt->data + cumul_size, (pkt->size - cumul_size) * 8);
-                if (avpriv_ac3_parse_header(&gbc, &hdr) < 0)
+                GetBitContext gbc;
+                int i, ret;
+                ret = avpriv_ac3_parse_header(&hdr, pkt->data + cumul_size, pkt->size - cumul_size);
+                if (ret < 0)
                     return AVERROR_INVALIDDATA;
                 if (hdr->frame_type != EAC3_FRAME_TYPE_DEPENDENT)
                     return AVERROR(EINVAL);
-                cumul_size += hdr->frame_size;
                 info->substream[parent].num_dep_sub++;
+                ret /= 8;
 
                 /* header is parsed up to lfeon, but custom channel map may be needed */
+                init_get_bits8(&gbc, pkt->data + cumul_size + ret, pkt->size - cumul_size - ret);
                 /* skip bsid */
                 skip_bits(&gbc, 5);
                 /* skip volume control params */
@@ -427,6 +427,7 @@ static int handle_eac3(MOVMuxContext *mov, AVPacket *pkt, MOVTrack *track)
                     info->substream[parent].chan_loc |= (get_bits(&gbc, 16) >> 5) & 0x1f;
                 else
                     info->substream[parent].chan_loc |= hdr->channel_mode;
+                cumul_size += hdr->frame_size;
             }
         }
     }