LucasArts SMUSH VIMA audio decoder

Signed-off-by: Paul B Mahol <onemda@gmail.com>

1 files changed, 236 insertions, 0 deletions

diff --git a/libavcodec/vima.c b/libavcodec/vima.c
new file mode 100644
index 0000000000..7c9a22bfe7
--- /dev/null
+++ b/libavcodec/vima.c
@@ -0,0 +1,236 @@
+/*
+ * LucasArt VIMA decoder
+ * Copyright (c) 2012 Paul B Mahol
+ *
+ * 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 "libavutil/audioconvert.h"
+#include "avcodec.h"
+#include "get_bits.h"
+#include "adpcm_data.h"
+
+typedef struct {
+    AVFrame     frame;
+    uint16_t    predict_table[5786 * 2];
+} VimaContext;
+
+static const uint8_t size_table[] =
+{
+    4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
+    4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
+    4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
+    5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5,
+    6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
+    7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7
+};
+
+static const int8_t index_table1[] =
+{
+    -1, 4, -1, 4
+};
+
+static const int8_t index_table2[] =
+{
+    -1, -1, 2, 6, -1, -1, 2, 6
+};
+
+static const int8_t index_table3[] =
+{
+    -1, -1, -1, -1, 1, 2, 4, 6,
+    -1, -1, -1, -1, 1, 2, 4, 6
+};
+
+static const int8_t index_table4[] =
+{
+    -1, -1, -1, -1, -1, -1, -1, -1,
+     1,  1,  1,  2,  2,  4,  5,  6,
+    -1, -1, -1, -1, -1, -1, -1, -1,
+     1,  1,  1,  2,  2,  4,  5,  6
+};
+
+static const int8_t index_table5[] =
+{
+    -1, -1, -1, -1, -1, -1, -1, -1,
+    -1, -1, -1, -1, -1, -1, -1, -1,
+     1,  1,  1,  1,  1,  2,  2,  2,
+     2,  4,  4,  4,  5,  5,  6,  6,
+    -1, -1, -1, -1, -1, -1, -1, -1,
+    -1, -1, -1, -1, -1, -1, -1, -1,
+     1,  1,  1,  1,  1,  2,  2,  2,
+     2,  4,  4,  4,  5,  5,  6,  6
+};
+
+static const int8_t index_table6[] =
+{
+    -1, -1, -1, -1, -1, -1, -1, -1,
+    -1, -1, -1, -1, -1, -1, -1, -1,
+    -1, -1, -1, -1, -1, -1, -1, -1,
+    -1, -1, -1, -1, -1, -1, -1, -1,
+     1,  1,  1,  1,  1,  1,  1,  1,
+     1,  1,  2,  2,  2,  2,  2,  2,
+     2,  2,  4,  4,  4,  4,  4,  4,
+     5,  5,  5,  5,  6,  6,  6,  6,
+    -1, -1, -1, -1, -1, -1, -1, -1,
+    -1, -1, -1, -1, -1, -1, -1, -1,
+    -1, -1, -1, -1, -1, -1, -1, -1,
+    -1, -1, -1, -1, -1, -1, -1, -1,
+     1,  1,  1,  1,  1,  1,  1,  1,
+     1,  1,  2,  2,  2,  2,  2,  2,
+     2,  2,  4,  4,  4,  4,  4,  4,
+     5,  5,  5,  5,  6,  6,  6,  6
+};
+
+static const int8_t* const step_index_tables[] =
+{
+    index_table1, index_table2, index_table3,
+    index_table4, index_table5, index_table6
+};
+
+static av_cold int decode_init(AVCodecContext *avctx)
+{
+    VimaContext *vima = avctx->priv_data;
+    int         start_pos;
+
+    for (start_pos = 0; start_pos < 64; start_pos++) {
+        unsigned int dest_pos, table_pos;
+
+        for (table_pos = 0, dest_pos = start_pos;
+             table_pos < FF_ARRAY_ELEMS(ff_adpcm_step_table);
+             table_pos++, dest_pos += 64) {
+            int put = 0, count, table_value;
+
+            table_value = ff_adpcm_step_table[table_pos];
+            for (count = 32; count != 0; count >>= 1) {
+                if (start_pos & count)
+                    put += table_value;
+                table_value >>= 1;
+            }
+            vima->predict_table[dest_pos] = put;
+        }
+    }
+
+    avcodec_get_frame_defaults(&vima->frame);
+    avctx->coded_frame = &vima->frame;
+    avctx->sample_fmt  = AV_SAMPLE_FMT_S16;
+
+    return 0;
+}
+
+static int decode_frame(AVCodecContext *avctx, void *data,
+                        int *got_frame_ptr, AVPacket *pkt)
+{
+    GetBitContext  gb;
+    VimaContext    *vima = avctx->priv_data;
+    int16_t        pcm_data[2];
+    uint32_t       samples;
+    int8_t         channel_hint[2];
+    int            ret, chan, channels = 1;
+
+    init_get_bits(&gb, pkt->data, pkt->size * 8);
+
+    if (pkt->size < 13)
+        return AVERROR_INVALIDDATA;
+
+    samples = get_bits_long(&gb, 32);
+    if (samples == 0xffffffff) {
+        skip_bits_long(&gb, 32);
+        samples = get_bits_long(&gb, 32);
+    }
+
+    if (samples > pkt->size * 2)
+        return AVERROR_INVALIDDATA;
+
+    channel_hint[0] = get_sbits(&gb, 8);
+    if (channel_hint[0] & 0x80) {
+        channel_hint[0] = ~channel_hint[0];
+        channels = 2;
+    }
+    avctx->channels = channels;
+    avctx->channel_layout = (channels == 2) ? AV_CH_LAYOUT_STEREO :
+                                              AV_CH_LAYOUT_MONO;
+    pcm_data[0] = get_sbits(&gb, 16);
+    if (channels > 1) {
+        channel_hint[1] = get_sbits(&gb, 8);
+        pcm_data[1] = get_sbits(&gb, 16);
+    }
+
+    vima->frame.nb_samples = samples;
+    if ((ret = avctx->get_buffer(avctx, &vima->frame)) < 0) {
+        av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
+        return ret;
+    }
+
+    for (chan = 0; chan < channels; chan++) {
+        uint16_t *dest = (uint16_t*)vima->frame.data[0] + chan;
+        int step_index = channel_hint[chan];
+        int output = pcm_data[chan];
+        int sample;
+
+        for (sample = 0; sample < samples; sample++) {
+            int lookup_size, lookup, highbit, lowbits;
+
+            step_index  = av_clip(step_index, 0, 88);
+            lookup_size = size_table[step_index];
+            lookup      = get_bits(&gb, lookup_size);
+            highbit     = 1 << (lookup_size - 1);
+            lowbits     = highbit - 1;
+
+            if (lookup & highbit)
+                lookup ^= highbit;
+            else
+                highbit = 0;
+
+            if (lookup == lowbits) {
+                output = get_sbits(&gb, 16);
+            } else {
+                int predict_index, diff;
+
+                predict_index = (lookup << (7 - lookup_size)) | (step_index << 6);
+                predict_index = av_clip(predict_index, 0, 5785);
+                diff          = vima->predict_table[predict_index];
+                if (lookup)
+                    diff += ff_adpcm_step_table[step_index] >> (lookup_size - 1);
+                if (highbit)
+                    diff  = -diff;
+
+                output  = av_clip_int16(output + diff);
+            }
+
+            *dest = output;
+            dest += channels;
+
+            step_index += step_index_tables[lookup_size - 2][lookup];
+        }
+    }
+
+    *got_frame_ptr   = 1;
+    *(AVFrame *)data = vima->frame;
+
+    return pkt->size;
+}
+
+AVCodec ff_vima_decoder = {
+    .name           = "vima",
+    .type           = AVMEDIA_TYPE_AUDIO,
+    .id             = CODEC_ID_VIMA,
+    .priv_data_size = sizeof(VimaContext),
+    .init           = decode_init,
+    .decode         = decode_frame,
+    .capabilities   = CODEC_CAP_DR1,
+    .long_name      = NULL_IF_CONFIG_SMALL("LucasArts VIMA audio"),
+};