dca: Split code for handling the EXSS extension off into a separate file

1 files changed, 322 insertions, 0 deletions

diff --git a/libavcodec/dca_exss.c b/libavcodec/dca_exss.c
new file mode 100644
index 0000000000..a4fb29e6a7
--- /dev/null
+++ b/libavcodec/dca_exss.c
@@ -0,0 +1,322 @@
+/*
+ * DCA ExSS extension
+ *
+ * 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
+ */
+
+#include "libavutil/common.h"
+#include "libavutil/log.h"
+
+#include "dca.h"
+#include "dca_exss.h"
+#include "get_bits.h"
+
+/* extensions that reside in core substream */
+#define DCA_CORE_EXTS (DCA_EXT_XCH | DCA_EXT_XXCH | DCA_EXT_X96)
+
+/* these are unconfirmed but should be mostly correct */
+enum DCAExSSSpeakerMask {
+    DCA_EXSS_FRONT_CENTER          = 0x0001,
+    DCA_EXSS_FRONT_LEFT_RIGHT      = 0x0002,
+    DCA_EXSS_SIDE_REAR_LEFT_RIGHT  = 0x0004,
+    DCA_EXSS_LFE                   = 0x0008,
+    DCA_EXSS_REAR_CENTER           = 0x0010,
+    DCA_EXSS_FRONT_HIGH_LEFT_RIGHT = 0x0020,
+    DCA_EXSS_REAR_LEFT_RIGHT       = 0x0040,
+    DCA_EXSS_FRONT_HIGH_CENTER     = 0x0080,
+    DCA_EXSS_OVERHEAD              = 0x0100,
+    DCA_EXSS_CENTER_LEFT_RIGHT     = 0x0200,
+    DCA_EXSS_WIDE_LEFT_RIGHT       = 0x0400,
+    DCA_EXSS_SIDE_LEFT_RIGHT       = 0x0800,
+    DCA_EXSS_LFE2                  = 0x1000,
+    DCA_EXSS_SIDE_HIGH_LEFT_RIGHT  = 0x2000,
+    DCA_EXSS_REAR_HIGH_CENTER      = 0x4000,
+    DCA_EXSS_REAR_HIGH_LEFT_RIGHT  = 0x8000,
+};
+
+/**
+ * Return the number of channels in an ExSS speaker mask (HD)
+ */
+static int dca_exss_mask2count(int mask)
+{
+    /* count bits that mean speaker pairs twice */
+    return av_popcount(mask) +
+           av_popcount(mask & (DCA_EXSS_CENTER_LEFT_RIGHT      |
+                               DCA_EXSS_FRONT_LEFT_RIGHT       |
+                               DCA_EXSS_FRONT_HIGH_LEFT_RIGHT  |
+                               DCA_EXSS_WIDE_LEFT_RIGHT        |
+                               DCA_EXSS_SIDE_LEFT_RIGHT        |
+                               DCA_EXSS_SIDE_HIGH_LEFT_RIGHT   |
+                               DCA_EXSS_SIDE_REAR_LEFT_RIGHT   |
+                               DCA_EXSS_REAR_LEFT_RIGHT        |
+                               DCA_EXSS_REAR_HIGH_LEFT_RIGHT));
+}
+
+/**
+ * Skip mixing coefficients of a single mix out configuration (HD)
+ */
+static void dca_exss_skip_mix_coeffs(GetBitContext *gb, int channels, int out_ch)
+{
+    int i;
+
+    for (i = 0; i < channels; i++) {
+        int mix_map_mask = get_bits(gb, out_ch);
+        int num_coeffs = av_popcount(mix_map_mask);
+        skip_bits_long(gb, num_coeffs * 6);
+    }
+}
+
+/**
+ * Parse extension substream asset header (HD)
+ */
+static int dca_exss_parse_asset_header(DCAContext *s)
+{
+    int header_pos = get_bits_count(&s->gb);
+    int header_size;
+    int channels = 0;
+    int embedded_stereo = 0;
+    int embedded_6ch    = 0;
+    int drc_code_present;
+    int extensions_mask = 0;
+    int i, j;
+
+    if (get_bits_left(&s->gb) < 16)
+        return -1;
+
+    /* We will parse just enough to get to the extensions bitmask with which
+     * we can set the profile value. */
+
+    header_size = get_bits(&s->gb, 9) + 1;
+    skip_bits(&s->gb, 3); // asset index
+
+    if (s->static_fields) {
+        if (get_bits1(&s->gb))
+            skip_bits(&s->gb, 4); // asset type descriptor
+        if (get_bits1(&s->gb))
+            skip_bits_long(&s->gb, 24); // language descriptor
+
+        if (get_bits1(&s->gb)) {
+            /* How can one fit 1024 bytes of text here if the maximum value
+             * for the asset header size field above was 512 bytes? */
+            int text_length = get_bits(&s->gb, 10) + 1;
+            if (get_bits_left(&s->gb) < text_length * 8)
+                return -1;
+            skip_bits_long(&s->gb, text_length * 8); // info text
+        }
+
+        skip_bits(&s->gb, 5); // bit resolution - 1
+        skip_bits(&s->gb, 4); // max sample rate code
+        channels = get_bits(&s->gb, 8) + 1;
+
+        if (get_bits1(&s->gb)) { // 1-to-1 channels to speakers
+            int spkr_remap_sets;
+            int spkr_mask_size = 16;
+            int num_spkrs[7];
+
+            if (channels > 2)
+                embedded_stereo = get_bits1(&s->gb);
+            if (channels > 6)
+                embedded_6ch = get_bits1(&s->gb);
+
+            if (get_bits1(&s->gb)) {
+                spkr_mask_size = (get_bits(&s->gb, 2) + 1) << 2;
+                skip_bits(&s->gb, spkr_mask_size); // spkr activity mask
+            }
+
+            spkr_remap_sets = get_bits(&s->gb, 3);
+
+            for (i = 0; i < spkr_remap_sets; i++) {
+                /* std layout mask for each remap set */
+                num_spkrs[i] = dca_exss_mask2count(get_bits(&s->gb, spkr_mask_size));
+            }
+
+            for (i = 0; i < spkr_remap_sets; i++) {
+                int num_dec_ch_remaps = get_bits(&s->gb, 5) + 1;
+                if (get_bits_left(&s->gb) < 0)
+                    return -1;
+
+                for (j = 0; j < num_spkrs[i]; j++) {
+                    int remap_dec_ch_mask = get_bits_long(&s->gb, num_dec_ch_remaps);
+                    int num_dec_ch = av_popcount(remap_dec_ch_mask);
+                    skip_bits_long(&s->gb, num_dec_ch * 5); // remap codes
+                }
+            }
+        } else {
+            skip_bits(&s->gb, 3); // representation type
+        }
+    }
+
+    drc_code_present = get_bits1(&s->gb);
+    if (drc_code_present)
+        get_bits(&s->gb, 8); // drc code
+
+    if (get_bits1(&s->gb))
+        skip_bits(&s->gb, 5); // dialog normalization code
+
+    if (drc_code_present && embedded_stereo)
+        get_bits(&s->gb, 8); // drc stereo code
+
+    if (s->mix_metadata && get_bits1(&s->gb)) {
+        skip_bits(&s->gb, 1); // external mix
+        skip_bits(&s->gb, 6); // post mix gain code
+
+        if (get_bits(&s->gb, 2) != 3) // mixer drc code
+            skip_bits(&s->gb, 3); // drc limit
+        else
+            skip_bits(&s->gb, 8); // custom drc code
+
+        if (get_bits1(&s->gb)) // channel specific scaling
+            for (i = 0; i < s->num_mix_configs; i++)
+                skip_bits_long(&s->gb, s->mix_config_num_ch[i] * 6); // scale codes
+        else
+            skip_bits_long(&s->gb, s->num_mix_configs * 6); // scale codes
+
+        for (i = 0; i < s->num_mix_configs; i++) {
+            if (get_bits_left(&s->gb) < 0)
+                return -1;
+            dca_exss_skip_mix_coeffs(&s->gb, channels, s->mix_config_num_ch[i]);
+            if (embedded_6ch)
+                dca_exss_skip_mix_coeffs(&s->gb, 6, s->mix_config_num_ch[i]);
+            if (embedded_stereo)
+                dca_exss_skip_mix_coeffs(&s->gb, 2, s->mix_config_num_ch[i]);
+        }
+    }
+
+    switch (get_bits(&s->gb, 2)) {
+    case 0:
+        extensions_mask = get_bits(&s->gb, 12);
+        break;
+    case 1:
+        extensions_mask = DCA_EXT_EXSS_XLL;
+        break;
+    case 2:
+        extensions_mask = DCA_EXT_EXSS_LBR;
+        break;
+    case 3:
+        extensions_mask = 0; /* aux coding */
+        break;
+    }
+
+    /* not parsed further, we were only interested in the extensions mask */
+
+    if (get_bits_left(&s->gb) < 0)
+        return -1;
+
+    if (get_bits_count(&s->gb) - header_pos > header_size * 8) {
+        av_log(s->avctx, AV_LOG_WARNING, "Asset header size mismatch.\n");
+        return -1;
+    }
+    skip_bits_long(&s->gb, header_pos + header_size * 8 - get_bits_count(&s->gb));
+
+    if (extensions_mask & DCA_EXT_EXSS_XLL)
+        s->profile = FF_PROFILE_DTS_HD_MA;
+    else if (extensions_mask & (DCA_EXT_EXSS_XBR | DCA_EXT_EXSS_X96 |
+                                DCA_EXT_EXSS_XXCH))
+        s->profile = FF_PROFILE_DTS_HD_HRA;
+
+    if (!(extensions_mask & DCA_EXT_CORE))
+        av_log(s->avctx, AV_LOG_WARNING, "DTS core detection mismatch.\n");
+    if ((extensions_mask & DCA_CORE_EXTS) != s->core_ext_mask)
+        av_log(s->avctx, AV_LOG_WARNING,
+               "DTS extensions detection mismatch (%d, %d)\n",
+               extensions_mask & DCA_CORE_EXTS, s->core_ext_mask);
+
+    return 0;
+}
+
+/**
+ * Parse extension substream header (HD)
+ */
+void ff_dca_exss_parse_header(DCAContext *s)
+{
+    int ss_index;
+    int blownup;
+    int num_audiop = 1;
+    int num_assets = 1;
+    int active_ss_mask[8];
+    int i, j;
+
+    if (get_bits_left(&s->gb) < 52)
+        return;
+
+    skip_bits(&s->gb, 8); // user data
+    ss_index = get_bits(&s->gb, 2);
+
+    blownup = get_bits1(&s->gb);
+    skip_bits(&s->gb,  8 + 4 * blownup); // header_size
+    skip_bits(&s->gb, 16 + 4 * blownup); // hd_size
+
+    s->static_fields = get_bits1(&s->gb);
+    if (s->static_fields) {
+        skip_bits(&s->gb, 2); // reference clock code
+        skip_bits(&s->gb, 3); // frame duration code
+
+        if (get_bits1(&s->gb))
+            skip_bits_long(&s->gb, 36); // timestamp
+
+        /* a single stream can contain multiple audio assets that can be
+         * combined to form multiple audio presentations */
+
+        num_audiop = get_bits(&s->gb, 3) + 1;
+        if (num_audiop > 1) {
+            avpriv_request_sample(s->avctx,
+                                  "Multiple DTS-HD audio presentations");
+            /* ignore such streams for now */
+            return;
+        }
+
+        num_assets = get_bits(&s->gb, 3) + 1;
+        if (num_assets > 1) {
+            avpriv_request_sample(s->avctx, "Multiple DTS-HD audio assets");
+            /* ignore such streams for now */
+            return;
+        }
+
+        for (i = 0; i < num_audiop; i++)
+            active_ss_mask[i] = get_bits(&s->gb, ss_index + 1);
+
+        for (i = 0; i < num_audiop; i++)
+            for (j = 0; j <= ss_index; j++)
+                if (active_ss_mask[i] & (1 << j))
+                    skip_bits(&s->gb, 8); // active asset mask
+
+        s->mix_metadata = get_bits1(&s->gb);
+        if (s->mix_metadata) {
+            int mix_out_mask_size;
+
+            skip_bits(&s->gb, 2); // adjustment level
+            mix_out_mask_size  = (get_bits(&s->gb, 2) + 1) << 2;
+            s->num_mix_configs =  get_bits(&s->gb, 2) + 1;
+
+            for (i = 0; i < s->num_mix_configs; i++) {
+                int mix_out_mask        = get_bits(&s->gb, mix_out_mask_size);
+                s->mix_config_num_ch[i] = dca_exss_mask2count(mix_out_mask);
+            }
+        }
+    }
+
+    for (i = 0; i < num_assets; i++)
+        skip_bits_long(&s->gb, 16 + 4 * blownup);  // asset size
+
+    for (i = 0; i < num_assets; i++) {
+        if (dca_exss_parse_asset_header(s))
+            return;
+    }
+
+    /* not parsed further, we were only interested in the extensions mask
+     * from the asset header */
+}