avcodec/mlp_parser: split off shared code to its own file

Signed-off-by: James Almer <jamrial@gmail.com>

1 files changed, 215 insertions, 0 deletions

diff --git a/libavcodec/mlp_parse.c b/libavcodec/mlp_parse.c
new file mode 100644
index 0000000000..067735303c
--- /dev/null
+++ b/libavcodec/mlp_parse.c
@@ -0,0 +1,215 @@
+/*
+ * Copyright (c) 2007 Ian Caulfield
+ *
+ * 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 <stdint.h>
+
+#include "libavutil/channel_layout.h"
+#include "get_bits.h"
+#include "mlp_parse.h"
+#include "mlp.h"
+
+static const uint8_t mlp_quants[16] = {
+    16, 20, 24, 0, 0, 0, 0, 0,
+     0,  0,  0, 0, 0, 0, 0, 0,
+};
+
+static const uint8_t mlp_channels[32] = {
+    1, 2, 3, 4, 3, 4, 5, 3, 4, 5, 4, 5, 6, 4, 5, 4,
+    5, 6, 5, 5, 6, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+};
+
+static const uint64_t mlp_layout[32] = {
+    AV_CH_LAYOUT_MONO,
+    AV_CH_LAYOUT_STEREO,
+    AV_CH_LAYOUT_2_1,
+    AV_CH_LAYOUT_QUAD,
+    AV_CH_LAYOUT_STEREO|AV_CH_LOW_FREQUENCY,
+    AV_CH_LAYOUT_2_1|AV_CH_LOW_FREQUENCY,
+    AV_CH_LAYOUT_QUAD|AV_CH_LOW_FREQUENCY,
+    AV_CH_LAYOUT_SURROUND,
+    AV_CH_LAYOUT_4POINT0,
+    AV_CH_LAYOUT_5POINT0_BACK,
+    AV_CH_LAYOUT_SURROUND|AV_CH_LOW_FREQUENCY,
+    AV_CH_LAYOUT_4POINT0|AV_CH_LOW_FREQUENCY,
+    AV_CH_LAYOUT_5POINT1_BACK,
+    AV_CH_LAYOUT_4POINT0,
+    AV_CH_LAYOUT_5POINT0_BACK,
+    AV_CH_LAYOUT_SURROUND|AV_CH_LOW_FREQUENCY,
+    AV_CH_LAYOUT_4POINT0|AV_CH_LOW_FREQUENCY,
+    AV_CH_LAYOUT_5POINT1_BACK,
+    AV_CH_LAYOUT_QUAD|AV_CH_LOW_FREQUENCY,
+    AV_CH_LAYOUT_5POINT0_BACK,
+    AV_CH_LAYOUT_5POINT1_BACK,
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
+};
+
+static const uint8_t thd_chancount[13] = {
+//  LR    C   LFE  LRs LRvh  LRc LRrs  Cs   Ts  LRsd  LRw  Cvh  LFE2
+     2,   1,   1,   2,   2,   2,   2,   1,   1,   2,   2,   1,   1
+};
+
+static const uint64_t thd_layout[13] = {
+    AV_CH_FRONT_LEFT|AV_CH_FRONT_RIGHT,                     // LR
+    AV_CH_FRONT_CENTER,                                     // C
+    AV_CH_LOW_FREQUENCY,                                    // LFE
+    AV_CH_SIDE_LEFT|AV_CH_SIDE_RIGHT,                       // LRs
+    AV_CH_TOP_FRONT_LEFT|AV_CH_TOP_FRONT_RIGHT,             // LRvh
+    AV_CH_FRONT_LEFT_OF_CENTER|AV_CH_FRONT_RIGHT_OF_CENTER, // LRc
+    AV_CH_BACK_LEFT|AV_CH_BACK_RIGHT,                       // LRrs
+    AV_CH_BACK_CENTER,                                      // Cs
+    AV_CH_TOP_CENTER,                                       // Ts
+    AV_CH_SURROUND_DIRECT_LEFT|AV_CH_SURROUND_DIRECT_RIGHT, // LRsd
+    AV_CH_WIDE_LEFT|AV_CH_WIDE_RIGHT,                       // LRw
+    AV_CH_TOP_FRONT_CENTER,                                 // Cvh
+    AV_CH_LOW_FREQUENCY_2,                                  // LFE2
+};
+
+static int mlp_samplerate(int in)
+{
+    if (in == 0xF)
+        return 0;
+
+    return (in & 8 ? 44100 : 48000) << (in & 7) ;
+}
+
+static int truehd_channels(int chanmap)
+{
+    int channels = 0, i;
+
+    for (i = 0; i < 13; i++)
+        channels += thd_chancount[i] * ((chanmap >> i) & 1);
+
+    return channels;
+}
+
+static uint64_t truehd_layout(int chanmap)
+{
+    int i;
+    uint64_t layout = 0;
+
+    for (i = 0; i < 13; i++)
+        layout |= thd_layout[i] * ((chanmap >> i) & 1);
+
+    return layout;
+}
+
+static int mlp_get_major_sync_size(const uint8_t * buf, int bufsize)
+{
+    int has_extension, extensions = 0;
+    int size = 28;
+    if (bufsize < 28)
+        return -1;
+
+    if (AV_RB32(buf) == 0xf8726fba) {
+        has_extension = buf[25] & 1;
+        if (has_extension) {
+            extensions = buf[26] >> 4;
+            size += 2 + extensions * 2;
+        }
+    }
+    return size;
+}
+
+/** Read a major sync info header - contains high level information about
+ *  the stream - sample rate, channel arrangement etc. Most of this
+ *  information is not actually necessary for decoding, only for playback.
+ *  gb must be a freshly initialized GetBitContext with no bits read.
+ */
+
+int ff_mlp_read_major_sync(void *log, MLPHeaderInfo *mh, GetBitContext *gb)
+{
+    int ratebits, channel_arrangement, header_size;
+    uint16_t checksum;
+
+    av_assert1(get_bits_count(gb) == 0);
+
+    header_size = mlp_get_major_sync_size(gb->buffer, gb->size_in_bits >> 3);
+    if (header_size < 0 || gb->size_in_bits < header_size << 3) {
+        av_log(log, AV_LOG_ERROR, "packet too short, unable to read major sync\n");
+        return -1;
+    }
+
+    checksum = ff_mlp_checksum16(gb->buffer, header_size - 2);
+    if (checksum != AV_RL16(gb->buffer+header_size-2)) {
+        av_log(log, AV_LOG_ERROR, "major sync info header checksum error\n");
+        return AVERROR_INVALIDDATA;
+    }
+
+    if (get_bits_long(gb, 24) != 0xf8726f) /* Sync words */
+        return AVERROR_INVALIDDATA;
+
+    mh->stream_type = get_bits(gb, 8);
+    mh->header_size = header_size;
+
+    if (mh->stream_type == 0xbb) {
+        mh->group1_bits = mlp_quants[get_bits(gb, 4)];
+        mh->group2_bits = mlp_quants[get_bits(gb, 4)];
+
+        ratebits = get_bits(gb, 4);
+        mh->group1_samplerate = mlp_samplerate(ratebits);
+        mh->group2_samplerate = mlp_samplerate(get_bits(gb, 4));
+
+        skip_bits(gb, 11);
+
+        mh->channel_arrangement=
+        channel_arrangement    = get_bits(gb, 5);
+        mh->channels_mlp       = mlp_channels[channel_arrangement];
+        mh->channel_layout_mlp = mlp_layout[channel_arrangement];
+    } else if (mh->stream_type == 0xba) {
+        mh->group1_bits = 24; // TODO: Is this information actually conveyed anywhere?
+        mh->group2_bits = 0;
+
+        ratebits = get_bits(gb, 4);
+        mh->group1_samplerate = mlp_samplerate(ratebits);
+        mh->group2_samplerate = 0;
+
+        skip_bits(gb, 4);
+
+        mh->channel_modifier_thd_stream0 = get_bits(gb, 2);
+        mh->channel_modifier_thd_stream1 = get_bits(gb, 2);
+
+        mh->channel_arrangement=
+        channel_arrangement            = get_bits(gb, 5);
+        mh->channels_thd_stream1       = truehd_channels(channel_arrangement);
+        mh->channel_layout_thd_stream1 = truehd_layout(channel_arrangement);
+
+        mh->channel_modifier_thd_stream2 = get_bits(gb, 2);
+
+        channel_arrangement            = get_bits(gb, 13);
+        mh->channels_thd_stream2       = truehd_channels(channel_arrangement);
+        mh->channel_layout_thd_stream2 = truehd_layout(channel_arrangement);
+    } else
+        return AVERROR_INVALIDDATA;
+
+    mh->access_unit_size = 40 << (ratebits & 7);
+    mh->access_unit_size_pow2 = 64 << (ratebits & 7);
+
+    skip_bits_long(gb, 48);
+
+    mh->is_vbr = get_bits1(gb);
+
+    mh->peak_bitrate = (get_bits(gb, 15) * mh->group1_samplerate + 8) >> 4;
+
+    mh->num_substreams = get_bits(gb, 4);
+
+    skip_bits_long(gb, 4 + (header_size - 17) * 8);
+
+    return 0;
+}