/*
  * Interplay ACM decoder
  *
  * Copyright (c) 2004-2008 Marko Kreen
  * Copyright (c) 2008 Adam Gashlin
  * Copyright (c) 2015 Paul B Mahol
  *
  * Permission to use, copy, modify, and distribute this software for any
  * purpose with or without fee is hereby granted, provided that the above
  * copyright notice and this permission notice appear in all copies.
  *
  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 
 #include "libavutil/intreadwrite.h"

 #define BITSTREAM_READER_LE

 #include "avcodec.h"

 #include "get_bits.h"
 #include "internal.h"
 
 static const int8_t map_1bit[]      = { -1, +1 };
 static const int8_t map_2bit_near[] = { -2, -1, +1, +2 };
 static const int8_t map_2bit_far[]  = { -3, -2, +2, +3 };
 static const int8_t map_3bit[]      = { -4, -3, -2, -1, +1, +2, +3, +4 };
 
 static int mul_3x3 [3 * 3 * 3];
 static int mul_3x5 [5 * 5 * 5];
 static int mul_2x11[11  *  11];
 
 typedef struct InterplayACMContext {
     GetBitContext gb;
     uint8_t *bitstream;
     int max_framesize;
     int bitstream_size;
     int bitstream_index;
 
     int level;
     int rows;
     int cols;
     int wrapbuf_len;
     int block_len;
     int skip;
 
     int *block;
     int *wrapbuf;
     int *ampbuf;
     int *midbuf;
 } InterplayACMContext;
 
 static av_cold int decode_init(AVCodecContext *avctx)
 {
     InterplayACMContext *s = avctx->priv_data;
     int x1, x2, x3;
 
     if (avctx->extradata_size < 14)
         return AVERROR_INVALIDDATA;
 

     if (avctx->channels <= 0) {
         av_log(avctx, AV_LOG_ERROR, "Invalid number of channels: %d\n", avctx->channels);
         return AVERROR_INVALIDDATA;
     }
 

     s->level = AV_RL16(avctx->extradata + 12) & 0xf;
     s->rows  = AV_RL16(avctx->extradata + 12) >>  4;
     s->cols  = 1 << s->level;
     s->wrapbuf_len = 2 * s->cols - 2;
     s->block_len = s->rows * s->cols;
     s->max_framesize = s->block_len;
 
     s->block   = av_calloc(s->block_len, sizeof(int));
     s->wrapbuf = av_calloc(s->wrapbuf_len, sizeof(int));
     s->ampbuf  = av_calloc(0x10000, sizeof(int));

     s->bitstream = av_calloc(s->max_framesize + AV_INPUT_BUFFER_PADDING_SIZE / sizeof(*s->bitstream) + 1, sizeof(*s->bitstream));

     if (!s->block || !s->wrapbuf || !s->ampbuf || !s->bitstream)
         return AVERROR(ENOMEM);
 
     s->midbuf  = s->ampbuf + 0x8000;
     avctx->sample_fmt = AV_SAMPLE_FMT_S16;
 
     for (x3 = 0; x3 < 3; x3++)
         for (x2 = 0; x2 < 3; x2++)
             for (x1 = 0; x1 < 3; x1++)
                 mul_3x3[x1 + x2 * 3 + x3* 3 * 3] = x1 + (x2 << 4) + (x3 << 8);
     for (x3 = 0; x3 < 5; x3++)
         for (x2 = 0; x2 < 5; x2++)
             for (x1 = 0; x1 < 5; x1++)
                 mul_3x5[x1 + x2 * 5 + x3 * 5 * 5] = x1 + (x2 << 4) + (x3 << 8);
     for (x2 = 0; x2 < 11; x2++)
         for (x1 = 0; x1 < 11; x1++)
             mul_2x11[x1 + x2 * 11] = x1 + (x2 << 4);
 
     return 0;
 }
 
 #define set_pos(s, r, c, idx) do {               \
         unsigned pos = ((r) << s->level) + (c);  \
         s->block[pos] = s->midbuf[(idx)];        \
     } while (0)
 
 static int zero(InterplayACMContext *s, unsigned ind, unsigned col)
 {
     unsigned i;
 
     for (i = 0; i < s->rows; i++)
         set_pos(s, i, col, 0);
     return 0;
 }
 
 static int bad(InterplayACMContext *s, unsigned ind, unsigned col)
 {
     return AVERROR_INVALIDDATA;
 }
 
 static int linear(InterplayACMContext *s, unsigned ind, unsigned col)
 {
     GetBitContext *gb = &s->gb;
     unsigned int i;
     int b, middle = 1 << (ind - 1);
 
     for (i = 0; i < s->rows; i++) {
         b = get_bits(gb, ind);
         set_pos(s, i, col, b - middle);
     }
     return 0;
 }
 
 static int k13(InterplayACMContext *s, unsigned ind, unsigned col)
 {
     GetBitContext *gb = &s->gb;
     unsigned i, b;
 
     for (i = 0; i < s->rows; i++) {
         b = get_bits1(gb);
         if (b == 0) {
             set_pos(s, i++, col, 0);
             if (i >= s->rows)
                 break;
             set_pos(s, i, col, 0);
             continue;
         }
         b = get_bits1(gb);
         if (b == 0) {
             set_pos(s, i, col, 0);
             continue;
         }
         b = get_bits1(gb);
         set_pos(s, i, col, map_1bit[b]);
     }
     return 0;
 }
 
 static int k12(InterplayACMContext *s, unsigned ind, unsigned col)
 {
     GetBitContext *gb = &s->gb;
     unsigned i, b;
 
     for (i = 0; i < s->rows; i++) {
         b = get_bits1(gb);
         if (b == 0) {
             set_pos(s, i, col, 0);
             continue;
         }
 
         b = get_bits1(gb);
         set_pos(s, i, col, map_1bit[b]);
     }
     return 0;
 }
 
 static int k24(InterplayACMContext *s, unsigned ind, unsigned col)
 {
     GetBitContext *gb = &s->gb;
     unsigned i, b;
 
     for (i = 0; i < s->rows; i++) {
         b = get_bits1(gb);
         if (b == 0) {
             set_pos(s, i++, col, 0);
             if (i >= s->rows) break;
             set_pos(s, i, col, 0);
             continue;
         }
 
         b = get_bits1(gb);
         if (b == 0) {
             set_pos(s, i, col, 0);
             continue;
         }
 
         b = get_bits(gb, 2);
         set_pos(s, i, col, map_2bit_near[b]);
     }
     return 0;
 }
 
 static int k23(InterplayACMContext *s, unsigned ind, unsigned col)
 {
     GetBitContext *gb = &s->gb;
     unsigned i, b;
 
     for (i = 0; i < s->rows; i++) {
         b = get_bits1(gb);
         if (b == 0) {
             set_pos(s, i, col, 0);
             continue;
         }
 
         b = get_bits(gb, 2);
         set_pos(s, i, col, map_2bit_near[b]);
     }
     return 0;
 }
 
 static int k35(InterplayACMContext *s, unsigned ind, unsigned col)
 {
     GetBitContext *gb = &s->gb;
     unsigned i, b;
 
     for (i = 0; i < s->rows; i++) {
         b = get_bits1(gb);
         if (b == 0) {
             set_pos(s, i++, col, 0);
             if (i >= s->rows)
                 break;
             set_pos(s, i, col, 0);
             continue;
         }
 
         b = get_bits1(gb);
         if (b == 0) {
             set_pos(s, i, col, 0);
             continue;
         }
 
         b = get_bits1(gb);
         if (b == 0) {
             b = get_bits1(gb);
             set_pos(s, i, col, map_1bit[b]);
             continue;
         }
 
         b = get_bits(gb, 2);
         set_pos(s, i, col, map_2bit_far[b]);
     }
     return 0;
 }
 
 static int k34(InterplayACMContext *s, unsigned ind, unsigned col)
 {
     GetBitContext *gb = &s->gb;
     unsigned i, b;
 
     for (i = 0; i < s->rows; i++) {
         b = get_bits1(gb);
         if (b == 0) {
             set_pos(s, i, col, 0);
             continue;
         }
 
         b = get_bits1(gb);
         if (b == 0) {
             b = get_bits1(gb);
             set_pos(s, i, col, map_1bit[b]);
             continue;
         }
 
         b = get_bits(gb, 2);
         set_pos(s, i, col, map_2bit_far[b]);
     }
     return 0;
 }
 
 static int k45(InterplayACMContext *s, unsigned ind, unsigned col)
 {
     GetBitContext *gb = &s->gb;
     unsigned i, b;
 
     for (i = 0; i < s->rows; i++) {
         b = get_bits1(gb);
         if (b == 0) {
             set_pos(s, i, col, 0); i++;
             if (i >= s->rows)
                 break;
             set_pos(s, i, col, 0);
             continue;
         }
 
         b = get_bits1(gb);
         if (b == 0) {
             set_pos(s, i, col, 0);
             continue;
         }
 
         b = get_bits(gb, 3);
         set_pos(s, i, col, map_3bit[b]);
     }
     return 0;
 }
 
 static int k44(InterplayACMContext *s, unsigned ind, unsigned col)
 {
     GetBitContext *gb = &s->gb;
     unsigned i, b;
 
     for (i = 0; i < s->rows; i++) {
         b = get_bits1(gb);
         if (b == 0) {
             set_pos(s, i, col, 0);
             continue;
         }
 
         b = get_bits(gb, 3);
         set_pos(s, i, col, map_3bit[b]);
     }
     return 0;
 }
 
 static int t15(InterplayACMContext *s, unsigned ind, unsigned col)
 {
     GetBitContext *gb = &s->gb;
     unsigned i, b;
     int n1, n2, n3;
 
     for (i = 0; i < s->rows; i++) {
         /* b = (x1) + (x2 * 3) + (x3 * 9) */
         b = get_bits(gb, 5);

         if (b > 26) {
             av_log(NULL, AV_LOG_ERROR, "Too large b = %d > 26\n", b);
             return AVERROR_INVALIDDATA;
         }

 
         n1 =  (mul_3x3[b] & 0x0F) - 1;
         n2 = ((mul_3x3[b] >> 4) & 0x0F) - 1;
         n3 = ((mul_3x3[b] >> 8) & 0x0F) - 1;
 
         set_pos(s, i++, col, n1);
         if (i >= s->rows)
             break;
         set_pos(s, i++, col, n2);
         if (i >= s->rows)
             break;
         set_pos(s, i, col, n3);
     }
     return 0;
 }
 
 static int t27(InterplayACMContext *s, unsigned ind, unsigned col)
 {
     GetBitContext *gb = &s->gb;
     unsigned i, b;
     int n1, n2, n3;
 
     for (i = 0; i < s->rows; i++) {
         /* b = (x1) + (x2 * 5) + (x3 * 25) */
         b = get_bits(gb, 7);

         if (b > 124) {
             av_log(NULL, AV_LOG_ERROR, "Too large b = %d > 124\n", b);
             return AVERROR_INVALIDDATA;
         }

 
         n1 =  (mul_3x5[b] & 0x0F) - 2;
         n2 = ((mul_3x5[b] >> 4) & 0x0F) - 2;
         n3 = ((mul_3x5[b] >> 8) & 0x0F) - 2;
 
         set_pos(s, i++, col, n1);
         if (i >= s->rows)
             break;
         set_pos(s, i++, col, n2);
         if (i >= s->rows)
             break;
         set_pos(s, i, col, n3);
     }
     return 0;
 }
 
 static int t37(InterplayACMContext *s, unsigned ind, unsigned col)
 {
     GetBitContext *gb = &s->gb;
     unsigned i, b;
     int n1, n2;
     for (i = 0; i < s->rows; i++) {
         /* b = (x1) + (x2 * 11) */
         b = get_bits(gb, 7);

         if (b > 120) {
             av_log(NULL, AV_LOG_ERROR, "Too large b = %d > 120\n", b);
             return AVERROR_INVALIDDATA;
         }

 
         n1 =  (mul_2x11[b] & 0x0F) - 5;
         n2 = ((mul_2x11[b] >> 4) & 0x0F) - 5;
 
         set_pos(s, i++, col, n1);
         if (i >= s->rows)
             break;
         set_pos(s, i, col, n2);
     }
     return 0;
 }
 
 typedef int (*filler)(InterplayACMContext *s, unsigned ind, unsigned col);
 
 static const filler filler_list[] = {
     zero,   bad,    bad,    linear,
     linear, linear, linear, linear,
     linear, linear, linear, linear,
     linear, linear, linear, linear,
     linear, k13,    k12,    t15,
     k24,    k23,    t27,    k35,
     k34,    bad,    k45,    k44,
     bad,    t37,    bad,    bad,
 };
 
 static int fill_block(InterplayACMContext *s)
 {
     GetBitContext *gb = &s->gb;
     unsigned i, ind;
     int ret;
 
     for (i = 0; i < s->cols; i++) {
         ind = get_bits(gb, 5);
         ret = filler_list[ind](s, ind, i);
         if (ret < 0)
             return ret;
     }
     return 0;
 }
 
 static void juggle(int *wrap_p, int *block_p, unsigned sub_len, unsigned sub_count)
 {
     unsigned i, j;
     int *p, r0, r1, r2, r3;
 
     for (i = 0; i < sub_len; i++) {
         p = block_p;
         r0 = wrap_p[0];
         r1 = wrap_p[1];
         for (j = 0; j < sub_count/2; j++) {
             r2 = *p;
             *p = r1 * 2 + (r0 + r2);
             p += sub_len;
             r3 = *p;
             *p = r2 * 2 - (r1 + r3);
             p += sub_len;
             r0 = r2;
             r1 = r3;
         }
 
         *wrap_p++ = r0;
         *wrap_p++ = r1;
         block_p++;
     }
 }
 
 static void juggle_block(InterplayACMContext *s)
 {
     unsigned sub_count, sub_len, todo_count, step_subcount, i;
     int *wrap_p, *block_p, *p;
 
     /* juggle only if subblock_len > 1 */
     if (s->level == 0)
         return;
 
     /* 2048 / subblock_len */
     if (s->level > 9)
         step_subcount = 1;
     else
         step_subcount = (2048 >> s->level) - 2;
 
     /* Apply juggle()  (rows)x(cols)
      * from (step_subcount * 2)            x (subblock_len/2)
      * to   (step_subcount * subblock_len) x (1)
      */
     todo_count = s->rows;
     block_p = s->block;
     while (1) {
         wrap_p = s->wrapbuf;
         sub_count = step_subcount;
         if (sub_count > todo_count)
             sub_count = todo_count;
 
         sub_len = s->cols / 2;
         sub_count *= 2;
 
         juggle(wrap_p, block_p, sub_len, sub_count);
         wrap_p += sub_len * 2;
 
         for (i = 0, p = block_p; i < sub_count; i++) {
             p[0]++;
             p += sub_len;
         }
 
         while (sub_len > 1) {
             sub_len /= 2;
             sub_count *= 2;
             juggle(wrap_p, block_p, sub_len, sub_count);
             wrap_p += sub_len * 2;
         }
 
         if (todo_count <= step_subcount)
             break;
 
         todo_count -= step_subcount;
         block_p += step_subcount << s->level;
     }
 }
 
 static int decode_block(InterplayACMContext *s)
 {
     GetBitContext *gb = &s->gb;
     int pwr, count, val, i, x, ret;
 
     pwr = get_bits(gb, 4);
     val = get_bits(gb, 16);
 
     count = 1 << pwr;
 
     for (i = 0, x = 0; i < count; i++) {
         s->midbuf[i] = x;
         x += val;
     }
 
     for (i = 1, x = -val; i <= count; i++) {
         s->midbuf[-i] = x;

         x -= (unsigned)val;

     }
 
     ret = fill_block(s);
     if (ret < 0)
         return ret;
 
     juggle_block(s);
 
     return 0;
 }
 
 static int decode_frame(AVCodecContext *avctx, void *data,
                         int *got_frame_ptr, AVPacket *pkt)
 {
     InterplayACMContext *s = avctx->priv_data;
     GetBitContext *gb = &s->gb;
     AVFrame *frame = data;
     const uint8_t *buf;
     int16_t *samples;
     int ret, n, buf_size, input_buf_size;
 
     if (!pkt->size && !s->bitstream_size) {
         *got_frame_ptr = 0;
         return 0;
     }
 
     buf_size = FFMIN(pkt->size, s->max_framesize - s->bitstream_size);
     input_buf_size = buf_size;
     if (s->bitstream_index + s->bitstream_size + buf_size > s->max_framesize) {
         memmove(s->bitstream, &s->bitstream[s->bitstream_index], s->bitstream_size);
         s->bitstream_index = 0;
     }
     if (pkt->data)
         memcpy(&s->bitstream[s->bitstream_index + s->bitstream_size], pkt->data, buf_size);
     buf                = &s->bitstream[s->bitstream_index];
     buf_size          += s->bitstream_size;
     s->bitstream_size  = buf_size;
     if (buf_size < s->max_framesize && pkt->data) {
         *got_frame_ptr = 0;
         return input_buf_size;
     }
 
     if ((ret = init_get_bits8(gb, buf, buf_size)) < 0)
         return ret;
 
     frame->nb_samples = s->block_len / avctx->channels;
     if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
         return ret;
 
     skip_bits(gb, s->skip);
     ret = decode_block(s);
     if (ret < 0)
         return ret;
 
     samples = (int16_t *)frame->data[0];
     for (n = 0; n < frame->nb_samples * avctx->channels; n++) {
         int val = s->block[n] >> s->level;
         *samples++ = val;
     }
 
     *got_frame_ptr = 1;
     s->skip = get_bits_count(gb) - 8 * (get_bits_count(gb) / 8);
     n = get_bits_count(gb) / 8;
 
     if (n > buf_size && pkt->data) {
         s->bitstream_size = 0;
         s->bitstream_index = 0;
         return AVERROR_INVALIDDATA;
     }
 
     if (s->bitstream_size) {
         s->bitstream_index += n;
         s->bitstream_size  -= n;
         return input_buf_size;
     }
     return n;
 }
 
 static av_cold int decode_close(AVCodecContext *avctx)
 {
     InterplayACMContext *s = avctx->priv_data;
 
     av_freep(&s->block);
     av_freep(&s->wrapbuf);
     av_freep(&s->ampbuf);
     av_freep(&s->bitstream);
     s->bitstream_size = 0;
 
     return 0;
 }
 
 AVCodec ff_interplay_acm_decoder = {
     .name           = "interplayacm",
     .long_name      = NULL_IF_CONFIG_SMALL("Interplay ACM"),
     .type           = AVMEDIA_TYPE_AUDIO,
     .id             = AV_CODEC_ID_INTERPLAY_ACM,
     .init           = decode_init,
     .close          = decode_close,
     .decode         = decode_frame,
     .capabilities   = AV_CODEC_CAP_DELAY | AV_CODEC_CAP_DR1,
     .priv_data_size = sizeof(InterplayACMContext),
 };