Mimic decoder.

Originally committed as revision 12491 to svn://svn.ffmpeg.org/ffmpeg/trunk

Changelog

@@ -113,6 +113,7 @@ version <next>
 - QT variant of IMA ADPCM encoder
 - VFW grabber
 - Ipod/Iphone compatible mp4 muxer
+- Mimic decoder
 
 version 0.4.9-pre1:
 

MAINTAINERS

@@ -145,6 +145,7 @@ Codecs:
   loco.c                                Kostya Shishkov
   lzo.h, lzo.c                          Reimar Doeffinger
   mdec.c                                Michael Niedermayer
+  mimic.c                               Ramiro Polla
   mjpeg.c                               Michael Niedermayer
   mpc*                                  Kostya Shishkov
   mpeg12.c, mpeg12data.h                Michael Niedermayer

libavcodec/Makefile

@@ -103,6 +103,7 @@ OBJS-$(CONFIG_LJPEG_ENCODER)           += ljpegenc.o mjpegenc.o mjpeg.o mpegvide
 OBJS-$(CONFIG_LOCO_DECODER)            += loco.o golomb.o
 OBJS-$(CONFIG_MACE3_DECODER)           += mace.o
 OBJS-$(CONFIG_MACE6_DECODER)           += mace.o
+OBJS-$(CONFIG_MIMIC_DECODER)           += mimic.o
 OBJS-$(CONFIG_MJPEG_DECODER)           += mjpegdec.o mjpeg.o
 OBJS-$(CONFIG_MJPEG_ENCODER)           += mjpegenc.o mjpeg.o mpegvideo_enc.o motion_est.o ratecontrol.o mpeg12data.o mpegvideo.o
 OBJS-$(CONFIG_MJPEGB_DECODER)          += mjpegbdec.o mjpegdec.o mjpeg.o

libavcodec/allcodecs.c

@@ -101,6 +101,7 @@ void avcodec_register_all(void)
     REGISTER_ENCODER (LJPEG, ljpeg);
     REGISTER_DECODER (LOCO, loco);
     REGISTER_DECODER (MDEC, mdec);
+    REGISTER_DECODER (MIMIC, mimic);
     REGISTER_ENCDEC  (MJPEG, mjpeg);
     REGISTER_DECODER (MJPEGB, mjpegb);
     REGISTER_DECODER (MMVIDEO, mmvideo);

libavcodec/avcodec.h

@@ -30,7 +30,7 @@
 #include "libavutil/avutil.h"
 
 #define LIBAVCODEC_VERSION_MAJOR 51
-#define LIBAVCODEC_VERSION_MINOR 51
+#define LIBAVCODEC_VERSION_MINOR 52
 #define LIBAVCODEC_VERSION_MICRO  0
 
 #define LIBAVCODEC_VERSION_INT  AV_VERSION_INT(LIBAVCODEC_VERSION_MAJOR, \
@@ -177,6 +177,7 @@ enum CodecID {
     CODEC_ID_SUNRAST,
     CODEC_ID_INDEO4,
     CODEC_ID_INDEO5,
+    CODEC_ID_MIMIC,
 
     /* various PCM "codecs" */
     CODEC_ID_PCM_S16LE= 0x10000,

libavcodec/mimic.c

+/*
+ * Copyright (C) 2005  Ole Andr Vadla Ravns <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,
+};