--- /dev/null
+/*
+ * Copyright (C) 2005 Ole André Vadla Ravnås <oleavr@gmail.com>
+ * Copyright (C) 2008 Ramiro Polla <ramiro@lisha.ufsc.br>
+ *
+ * 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 <stdlib.h>
+#include <string.h>
+#include <stdint.h>
+
+#include "avcodec.h"
+#include "bitstream.h"
+#include "dsputil.h"
+
+#define MIMIC_HEADER_SIZE 20
+
+typedef struct {
+ AVCodecContext *avctx;
+
+ int num_vblocks[3];
+ int num_hblocks[3];
+
+ uint8_t *swap_buf;
+ int swap_buf_size;
+
+ int cur_index;
+ int prev_index;
+
+ AVFrame buf_ptrs [16];
+ AVPicture flipped_ptrs[16];
+
+ DECLARE_ALIGNED_16(DCTELEM, dct_block[64]);
+
+ GetBitContext gb;
+ ScanTable scantable;
+ DSPContext dsp;
+ VLC vlc1;
+} MimicContext;
+
+static const uint32_t huffcodes[] = {
+ 0x0000000a, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
+ 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
+ 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x0000000b,
+ 0x0000001b, 0x00000038, 0x00000078, 0x00000079, 0x0000007a, 0x000000f9,
+ 0x000000fa, 0x000003fb, 0x000007f8, 0x000007f9, 0x000007fa, 0x000007fb,
+ 0x00000ff8, 0x00000ff9, 0x00000001, 0x00000039, 0x0000007b, 0x000000fb,
+ 0x000001f8, 0x000001f9, 0x00000ffa, 0x00000ffb, 0x00001ff8, 0x00001ff9,
+ 0x00001ffa, 0x00001ffb, 0x00003ff8, 0x00003ff9, 0x00003ffa, 0x00000000,
+ 0x00000004, 0x0000003a, 0x000001fa, 0x00003ffb, 0x00007ff8, 0x00007ff9,
+ 0x00007ffa, 0x00007ffb, 0x0000fff8, 0x0000fff9, 0x0000fffa, 0x0000fffb,
+ 0x0001fff8, 0x0001fff9, 0x0001fffa, 0x00000000, 0x0000000c, 0x000000f8,
+ 0x000001fb, 0x0001fffb, 0x0003fff8, 0x0003fff9, 0x0003fffa, 0x0003fffb,
+ 0x0007fff8, 0x0007fff9, 0x0007fffa, 0x0007fffb, 0x000ffff8, 0x000ffff9,
+ 0x000ffffa, 0x00000000, 0x0000001a, 0x000003f8, 0x000ffffb, 0x001ffff8,
+ 0x001ffff9, 0x001ffffa, 0x001ffffb, 0x003ffff8, 0x003ffff9, 0x003ffffa,
+ 0x003ffffb, 0x007ffff8, 0x007ffff9, 0x007ffffa, 0x007ffffb, 0x00000000,
+ 0x0000003b, 0x000003f9, 0x00fffff8, 0x00fffff9, 0x00fffffa, 0x00fffffb,
+ 0x01fffff8, 0x01fffff9, 0x01fffffa, 0x01fffffb, 0x03fffff8, 0x03fffff9,
+ 0x03fffffa, 0x03fffffb, 0x07fffff8, 0x00000000, 0x000003fa, 0x07fffff9,
+ 0x07fffffa, 0x07fffffb, 0x0ffffff8, 0x0ffffff9, 0x0ffffffa, 0x0ffffffb,
+ 0x1ffffff8, 0x1ffffff9, 0x1ffffffa, 0x1ffffffb, 0x3ffffff8, 0x3ffffff9,
+ 0x3ffffffa,
+};
+
+static const uint8_t huffbits[] = {
+ 4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+ 0, 0, 0, 0, 2, 4, 5, 6, 7, 7, 7, 8,
+ 8, 10, 11, 11, 11, 11, 12, 12, 2, 6, 7, 8,
+ 9, 9, 12, 12, 13, 13, 13, 13, 14, 14, 14, 0,
+ 3, 6, 9, 14, 15, 15, 15, 15, 16, 16, 16, 16,
+ 17, 17, 17, 0, 4, 8, 9, 17, 18, 18, 18, 18,
+ 19, 19, 19, 19, 20, 20, 20, 0, 5, 10, 20, 21,
+ 21, 21, 21, 22, 22, 22, 22, 23, 23, 23, 23, 0,
+ 6, 10, 24, 24, 24, 24, 25, 25, 25, 25, 26, 26,
+ 26, 26, 27, 0, 10, 27, 27, 27, 28, 28, 28, 28,
+ 29, 29, 29, 29, 30, 30, 30,
+};
+
+static const uint8_t col_zag[64] = {
+ 0, 8, 1, 2, 9, 16, 24, 17,
+ 10, 3, 4, 11, 18, 25, 32, 40,
+ 33, 26, 19, 12, 5, 6, 13, 20,
+ 27, 34, 41, 48, 56, 49, 42, 35,
+ 28, 21, 14, 7, 15, 22, 29, 36,
+ 43, 50, 57, 58, 51, 44, 37, 30,
+ 23, 31, 38, 45, 52, 59, 39, 46,
+ 53, 60, 61, 54, 47, 55, 62, 63
+};
+
+static int mimic_decode_init(AVCodecContext *avctx)
+{
+ MimicContext *ctx = avctx->priv_data;
+
+ ctx->prev_index = 0;
+ ctx->cur_index = 15;
+
+ if(init_vlc(&ctx->vlc1, 8, sizeof(huffbits)/sizeof(huffbits[0]),
+ huffbits, 1, 1, huffcodes, 4, 4, 0)) {
+ av_log(avctx, AV_LOG_ERROR, "error initializing vlc table\n");
+ return -1;
+ }
+ dsputil_init(&ctx->dsp, avctx);
+ ff_init_scantable(ctx->dsp.idct_permutation, &ctx->scantable, col_zag);
+
+ return 0;
+}
+
+const static int8_t vlcdec_lookup[9][64] = {
+ { 0, },
+ { -1, 1, },
+ { -3, 3, -2, 2, },
+ { -7, 7, -6, 6, -5, 5, -4, 4, },
+ { -15, 15, -14, 14, -13, 13, -12, 12,
+ -11, 11, -10, 10, -9, 9, -8, 8, },
+ { -31, 31, -30, 30, -29, 29, -28, 28,
+ -27, 27, -26, 26, -25, 25, -24, 24,
+ -23, 23, -22, 22, -21, 21, -20, 20,
+ -19, 19, -18, 18, -17, 17, -16, 16, },
+ { -63, 63, -62, 62, -61, 61, -60, 60,
+ -59, 59, -58, 58, -57, 57, -56, 56,
+ -55, 55, -54, 54, -53, 53, -52, 52,
+ -51, 51, -50, 50, -49, 49, -48, 48,
+ -47, 47, -46, 46, -45, 45, -44, 44,
+ -43, 43, -42, 42, -41, 41, -40, 40,
+ -39, 39, -38, 38, -37, 37, -36, 36,
+ -35, 35, -34, 34, -33, 33, -32, 32, },
+ { -127, 127, -126, 126, -125, 125, -124, 124,
+ -123, 123, -122, 122, -121, 121, -120, 120,
+ -119, 119, -118, 118, -117, 117, -116, 116,
+ -115, 115, -114, 114, -113, 113, -112, 112,
+ -111, 111, -110, 110, -109, 109, -108, 108,
+ -107, 107, -106, 106, -105, 105, -104, 104,
+ -103, 103, -102, 102, -101, 101, -100, 100,
+ -99, 99, -98, 98, -97, 97, -96, 96, },
+ { -95, 95, -94, 94, -93, 93, -92, 92,
+ -91, 91, -90, 90, -89, 89, -88, 88,
+ -87, 87, -86, 86, -85, 85, -84, 84,
+ -83, 83, -82, 82, -81, 81, -80, 80,
+ -79, 79, -78, 78, -77, 77, -76, 76,
+ -75, 75, -74, 74, -73, 73, -72, 72,
+ -71, 71, -70, 70, -69, 69, -68, 68,
+ -67, 67, -66, 66, -65, 65, -64, 64, },
+};
+
+static int vlc_decode_block(MimicContext *ctx, DCTELEM *block, int num_coeffs,
+ int qscale)
+{
+ unsigned int pos;
+
+ memset(block, 0, 64 * sizeof(DCTELEM));
+
+ block[0] = get_bits(&ctx->gb, 8) << 3;
+
+ for(pos = 1; pos < num_coeffs; pos++) {
+ uint32_t vlc, num_bits;
+ int value;
+ int coeff;
+
+ vlc = get_vlc2(&ctx->gb, ctx->vlc1.table, ctx->vlc1.bits, 4);
+ if(!vlc) /* end-of-block code */
+ return 1;
+ if(vlc == -1)
+ return 0;
+
+ /* pos_add and num_bits are coded in the vlc code */
+ pos += vlc&15; // pos_add
+ num_bits = vlc>>4; // num_bits
+
+ if(pos >= 64)
+ return 0;
+
+ value = get_bits(&ctx->gb, num_bits);
+
+ /* FFmpeg's IDCT behaves somewhat different from the original code, so
+ * a factor of 4 was added to the input */
+
+ coeff = vlcdec_lookup[num_bits][value];
+ if(pos<3)
+ coeff <<= 4;
+ else /* TODO Use >> 10 instead of / 1001 */
+ coeff = (coeff * qscale) / 1001;
+
+ block[ctx->scantable.permutated[pos]] = coeff;
+ }
+
+ return 1;
+}
+
+static int decode(MimicContext *ctx, int quality, int num_coeffs,
+ int is_iframe)
+{
+ int y, x, plane;
+
+ for(plane = 0; plane < 3; plane++) {
+ const int is_chroma = !!plane;
+ const int qscale = av_clip(10000-quality,is_chroma?1000:2000,10000)<<2;
+ const int stride = ctx->flipped_ptrs[ctx->cur_index].linesize[plane];
+ const uint8_t *src = ctx->flipped_ptrs[ctx->prev_index].data[plane];
+ uint8_t *dst = ctx->flipped_ptrs[ctx->cur_index ].data[plane];
+
+ for(y = 0 ; y < ctx->num_vblocks[plane] ; y++) {
+ for(x = 0; x < ctx->num_hblocks[plane]; x++) {
+
+ /* Check for a change condition in the current block.
+ * - iframes always change.
+ * - Luma plane changes on get_bits1 == 0
+ * - Chroma planes change on get_bits1 == 1 */
+ if(is_iframe || get_bits1(&ctx->gb) == is_chroma) {
+
+ /* Luma planes may use a backreference from the 15 last
+ * frames preceding the previous. (get_bits1 == 1)
+ * Chroma planes don't use backreferences. */
+ if(is_chroma || is_iframe || !get_bits1(&ctx->gb)) {
+
+ if(!vlc_decode_block(ctx, ctx->dct_block,
+ num_coeffs, qscale))
+ return 0;
+ ctx->dsp.idct_put(dst, stride, ctx->dct_block);
+ } else {
+ unsigned int backref = get_bits(&ctx->gb, 4);
+ int index = (ctx->cur_index+backref)&15;
+ uint8_t *p = ctx->flipped_ptrs[index].data[0];
+
+ if(p) {
+ p += src -
+ ctx->flipped_ptrs[ctx->prev_index].data[plane];
+ ctx->dsp.put_pixels_tab[1][0](dst, p, stride, 8);
+ } else {
+ av_log(ctx->avctx, AV_LOG_ERROR,
+ "No such backreference! Buggy sample.\n");
+ }
+ }
+ } else {
+ ctx->dsp.put_pixels_tab[1][0](dst, src, stride, 8);
+ }
+ src += 8;
+ dst += 8;
+ }
+ src += (stride - ctx->num_hblocks[plane])<<3;
+ dst += (stride - ctx->num_hblocks[plane])<<3;
+ }
+ }
+
+ return 1;
+}
+
+/**
+ * Flip the buffer upside-down and put it in the YVU order to match the
+ * way Mimic encodes frames.
+ */
+static void prepare_avpic(MimicContext *ctx, AVPicture *dst, AVPicture *src)
+{
+ int i;
+ dst->data[0] = src->data[0]+( ctx->avctx->height -1)*src->linesize[0];
+ dst->data[1] = src->data[2]+((ctx->avctx->height>>1)-1)*src->linesize[2];
+ dst->data[2] = src->data[1]+((ctx->avctx->height>>1)-1)*src->linesize[1];
+ for(i = 0 ; i < 3 ; i++)
+ dst->linesize[i] = -src->linesize[i];
+}
+
+static int mimic_decode_frame(AVCodecContext *avctx, void *data,
+ int *data_size, const uint8_t *buf, int buf_size)
+{
+ MimicContext *ctx = avctx->priv_data;
+ int is_pframe;
+ int width, height;
+ int quality, num_coeffs;
+ int swap_buf_size = buf_size - MIMIC_HEADER_SIZE;
+
+ /*
+ * Header structure:
+ * uint16_t I_dont_remember;
+ * uint16_t quality;
+ * uint16_t width;
+ * uint16_t height;
+ * uint32_t some_constant;
+ * uint32_t is_pframe;
+ * uint32_t num_coeffs;
+ */
+
+ if(buf_size < MIMIC_HEADER_SIZE) {
+ av_log(avctx, AV_LOG_ERROR, "insufficient data\n");
+ return -1;
+ }
+
+ width = AV_RL16(buf + 4);
+ height = AV_RL16(buf + 6);
+
+ if(!ctx->avctx) {
+ int i;
+
+ if(!(width == 160 && height == 120) &&
+ !(width == 320 && height == 240)) {
+ av_log(avctx, AV_LOG_ERROR, "invalid width/height!\n");
+ return -1;
+ }
+
+ ctx->avctx = avctx;
+ avctx->width = width;
+ avctx->height = height;
+ avctx->pix_fmt = PIX_FMT_YUV420P;
+ for(i = 0 ; i < 3 ; i++) {
+ ctx->num_vblocks[i] = -((-height) >> (3 + !!i));
+ ctx->num_hblocks[i] = width >> (3 + !!i) ;
+ }
+ } else if(width != ctx->avctx->width || height != ctx->avctx->height) {
+ av_log(avctx, AV_LOG_ERROR, "resolution changing is not supported\n");
+ return -1;
+ }
+
+ quality = AV_RL16(buf + 2);
+ is_pframe = AV_RL32(buf + 12);
+ num_coeffs = buf[16];
+
+ if(is_pframe && !ctx->buf_ptrs[ctx->prev_index].data[0]) {
+ av_log(avctx, AV_LOG_ERROR, "decoding must start with keyframe\n");
+ return -1;
+ }
+
+ ctx->buf_ptrs[ctx->cur_index].reference = 1;
+ if(avctx->get_buffer(avctx, &ctx->buf_ptrs[ctx->cur_index])) {
+ av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
+ return -1;
+ }
+
+ prepare_avpic(ctx, &ctx->flipped_ptrs[ctx->cur_index],
+ (AVPicture*) &ctx->buf_ptrs[ctx->cur_index]);
+
+ ctx->swap_buf = av_fast_realloc(ctx->swap_buf, &ctx->swap_buf_size,
+ swap_buf_size + FF_INPUT_BUFFER_PADDING_SIZE);
+ if(!ctx->swap_buf)
+ return AVERROR_NOMEM;
+
+ ctx->dsp.bswap_buf((uint32_t*)ctx->swap_buf,
+ (const uint32_t*) (buf + MIMIC_HEADER_SIZE),
+ swap_buf_size>>2);
+ init_get_bits(&ctx->gb, ctx->swap_buf, swap_buf_size << 3);
+
+ if(!decode(ctx, quality, num_coeffs, !is_pframe)) {
+ avctx->release_buffer(avctx, &ctx->buf_ptrs[ctx->cur_index]);
+ return -1;
+ }
+
+ ctx->buf_ptrs[ctx->cur_index].pict_type = is_pframe ? FF_P_TYPE:FF_I_TYPE;
+ *(AVFrame*)data = ctx->buf_ptrs[ctx->cur_index];
+ *data_size = sizeof(AVFrame);
+
+ ctx->prev_index = ctx->cur_index;
+ ctx->cur_index--;
+ ctx->cur_index &= 15;
+
+ /* Only release frames that aren't used for backreferences anymore */
+ if(ctx->buf_ptrs[ctx->cur_index].data[0])
+ avctx->release_buffer(avctx, &ctx->buf_ptrs[ctx->cur_index]);
+
+ return buf_size;
+}
+
+static int mimic_decode_end(AVCodecContext *avctx)
+{
+ MimicContext *ctx = avctx->priv_data;
+ int i;
+
+ av_free(ctx->swap_buf);
+ for(i = 0; i < 16; i++)
+ if(ctx->buf_ptrs[i].data[0])
+ avctx->release_buffer(avctx, &ctx->buf_ptrs[i]);
+ free_vlc(&ctx->vlc1);
+
+ return 0;
+}
+
+AVCodec mimic_decoder = {
+ "mimic",
+ CODEC_TYPE_VIDEO,
+ CODEC_ID_MIMIC,
+ sizeof(MimicContext),
+ mimic_decode_init,
+ NULL,
+ mimic_decode_end,
+ mimic_decode_frame,
+ CODEC_CAP_DR1,
+};