ffv1: split decoder and encoder

This is not based on lucas work due to code divergence (its less work this way
than trying to merge from a split based on 2 years outdated code)

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavcodec/Makefile

@@ -184,8 +184,8 @@ OBJS-$(CONFIG_EIGHTSVX_FIB_DECODER)    += 8svx.o
 OBJS-$(CONFIG_ESCAPE124_DECODER)       += escape124.o
 OBJS-$(CONFIG_ESCAPE130_DECODER)       += escape130.o
 OBJS-$(CONFIG_EXR_DECODER)             += exr.o
-OBJS-$(CONFIG_FFV1_DECODER)            += ffv1.o
-OBJS-$(CONFIG_FFV1_ENCODER)            += ffv1.o
+OBJS-$(CONFIG_FFV1_DECODER)            += ffv1dec.o ffv1.o
+OBJS-$(CONFIG_FFV1_ENCODER)            += ffv1enc.o ffv1.o
 OBJS-$(CONFIG_FFVHUFF_DECODER)         += huffyuv.o
 OBJS-$(CONFIG_FFVHUFF_ENCODER)         += huffyuv.o
 OBJS-$(CONFIG_FFWAVESYNTH_DECODER)     += ffwavesynth.o

libavcodec/ffv1.h

@@ -0,0 +1,212 @@
+/*
+ * FFV1 codec for libavcodec
+ *
+ * Copyright (c) 2003-2012 Michael Niedermayer <michaelni@gmx.at>
+ *
+ * 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
+ */
+
+#ifndef AVCODEC_FFV1_H
+#define AVCODEC_FFV1_H
+
+/**
+ * @file
+ * FF Video Codec 1 (a lossless codec)
+ */
+
+#include "libavutil/avassert.h"
+#include "libavutil/crc.h"
+#include "libavutil/opt.h"
+#include "libavutil/imgutils.h"
+#include "libavutil/pixdesc.h"
+#include "libavutil/timer.h"
+#include "avcodec.h"
+#include "internal.h"
+#include "dsputil.h"
+#include "rangecoder.h"
+#include "golomb.h"
+#include "mathops.h"
+
+#ifdef __INTEL_COMPILER
+#undef av_flatten
+#define av_flatten
+#endif
+
+#define MAX_PLANES 4
+#define CONTEXT_SIZE 32
+
+#define MAX_QUANT_TABLES 8
+#define MAX_CONTEXT_INPUTS 5
+
+extern const uint8_t ff_log2_run[41];
+
+typedef struct VlcState {
+    int16_t drift;
+    uint16_t error_sum;
+    int8_t bias;
+    uint8_t count;
+} VlcState;
+
+typedef struct PlaneContext {
+    int16_t quant_table[MAX_CONTEXT_INPUTS][256];
+    int quant_table_index;
+    int context_count;
+    uint8_t (*state)[CONTEXT_SIZE];
+    VlcState *vlc_state;
+    uint8_t interlace_bit_state[2];
+} PlaneContext;
+
+#define MAX_SLICES 256
+
+typedef struct FFV1Context {
+    AVClass *class;
+    AVCodecContext *avctx;
+    RangeCoder c;
+    GetBitContext gb;
+    PutBitContext pb;
+    uint64_t rc_stat[256][2];
+    uint64_t (*rc_stat2[MAX_QUANT_TABLES])[32][2];
+    int version;
+    int minor_version;
+    int width, height;
+    int chroma_h_shift, chroma_v_shift;
+    int chroma_planes;
+    int transparency;
+    int flags;
+    int picture_number;
+    AVFrame picture;
+    AVFrame last_picture;
+    int plane_count;
+    int ac;                              ///< 1=range coder <-> 0=golomb rice
+    int ac_byte_count;                   ///< number of bytes used for AC coding
+    PlaneContext plane[MAX_PLANES];
+    int16_t quant_table[MAX_CONTEXT_INPUTS][256];
+    int16_t quant_tables[MAX_QUANT_TABLES][MAX_CONTEXT_INPUTS][256];
+    int context_count[MAX_QUANT_TABLES];
+    uint8_t state_transition[256];
+    uint8_t (*initial_states[MAX_QUANT_TABLES])[32];
+    int run_index;
+    int colorspace;
+    int16_t *sample_buffer;
+    int gob_count;
+    int packed_at_lsb;
+    int ec;
+    int slice_damaged;
+    int key_frame_ok;
+
+    int quant_table_count;
+
+    DSPContext dsp;
+
+    struct FFV1Context *slice_context[MAX_SLICES];
+    int slice_count;
+    int num_v_slices;
+    int num_h_slices;
+    int slice_width;
+    int slice_height;
+    int slice_x;
+    int slice_y;
+    int bits_per_raw_sample;
+} FFV1Context;
+
+int ffv1_common_init(AVCodecContext *avctx);
+int ffv1_init_slice_state(FFV1Context *f, FFV1Context *fs);
+int ffv1_init_slices_state(FFV1Context *f);
+int ffv1_init_slice_contexts(FFV1Context *f);
+int ffv1_allocate_initial_states(FFV1Context *f);
+void ffv1_clear_slice_state(FFV1Context *f, FFV1Context *fs);
+int ffv1_common_end(AVCodecContext *avctx);
+
+static av_always_inline int fold(int diff, int bits)
+{
+    if (bits == 8)
+        diff = (int8_t)diff;
+    else {
+        diff +=  1 << (bits  - 1);
+        diff &= (1 <<  bits) - 1;
+        diff -=  1 << (bits  - 1);
+    }
+
+    return diff;
+}
+
+static inline int predict(int16_t *src, int16_t *last)
+{
+    const int LT = last[-1];
+    const int T  = last[0];
+    const int L  = src[-1];
+
+    return mid_pred(L, L + T - LT, T);
+}
+
+static inline int get_context(PlaneContext *p, int16_t *src,
+                              int16_t *last, int16_t *last2)
+{
+    const int LT = last[-1];
+    const int T  = last[0];
+    const int RT = last[1];
+    const int L  = src[-1];
+
+    if (p->quant_table[3][127]) {
+        const int TT = last2[0];
+        const int LL = src[-2];
+        return p->quant_table[0][(L - LT) & 0xFF] +
+               p->quant_table[1][(LT - T) & 0xFF] +
+               p->quant_table[2][(T - RT) & 0xFF] +
+               p->quant_table[3][(LL - L) & 0xFF] +
+               p->quant_table[4][(TT - T) & 0xFF];
+    } else
+        return p->quant_table[0][(L - LT) & 0xFF] +
+               p->quant_table[1][(LT - T) & 0xFF] +
+               p->quant_table[2][(T - RT) & 0xFF];
+}
+
+static inline void update_vlc_state(VlcState *const state, const int v)
+{
+    int drift = state->drift;
+    int count = state->count;
+    state->error_sum += FFABS(v);
+    drift            += v;
+
+    if (count == 128) { // FIXME: variable
+        count            >>= 1;
+        drift            >>= 1;
+        state->error_sum >>= 1;
+    }
+    count++;
+
+    if (drift <= -count) {
+        if (state->bias > -128)
+            state->bias--;
+
+        drift += count;
+        if (drift <= -count)
+            drift = -count + 1;
+    } else if (drift > 0) {
+        if (state->bias < 127)
+            state->bias++;
+
+        drift -= count;
+        if (drift > 0)
+            drift = 0;
+    }
+
+    state->drift = drift;
+    state->count = count;
+}
+
+#endif /* AVCODEC_FFV1_H */

libavcodec/ffv1dec.c

@@ -0,0 +1,843 @@
+/*
+ * FFV1 decoder
+ *
+ * Copyright (c) 2003-2012 Michael Niedermayer <michaelni@gmx.at>
+ *
+ * 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
+ */
+
+/**
+ * @file
+ * FF Video Codec 1 (a lossless codec) decoder
+ */
+
+#include "libavutil/avassert.h"
+#include "libavutil/crc.h"
+#include "libavutil/opt.h"
+#include "libavutil/imgutils.h"
+#include "libavutil/pixdesc.h"
+#include "libavutil/timer.h"
+#include "avcodec.h"
+#include "internal.h"
+#include "get_bits.h"
+#include "put_bits.h"
+#include "dsputil.h"
+#include "rangecoder.h"
+#include "golomb.h"
+#include "mathops.h"
+#include "ffv1.h"
+
+static inline av_flatten int get_symbol_inline(RangeCoder *c, uint8_t *state,
+                                               int is_signed)
+{
+    if (get_rac(c, state + 0))
+        return 0;
+    else {
+        int i, e, a;
+        e = 0;
+        while (get_rac(c, state + 1 + FFMIN(e, 9))) // 1..10
+            e++;
+
+        a = 1;
+        for (i = e - 1; i >= 0; i--)
+            a += a + get_rac(c, state + 22 + FFMIN(i, 9));  // 22..31
+
+        e = -(is_signed && get_rac(c, state + 11 + FFMIN(e, 10))); // 11..21
+        return (a ^ e) - e;
+    }
+}
+
+static av_noinline int get_symbol(RangeCoder *c, uint8_t *state, int is_signed)
+{
+    return get_symbol_inline(c, state, is_signed);
+}
+
+static inline int get_vlc_symbol(GetBitContext *gb, VlcState *const state,
+                                 int bits)
+{
+    int k, i, v, ret;
+
+    i = state->count;
+    k = 0;
+    while (i < state->error_sum) { // FIXME: optimize
+        k++;
+        i += i;
+    }
+
+    assert(k <= 8);
+
+    v = get_sr_golomb(gb, k, 12, bits);
+    av_dlog(NULL, "v:%d bias:%d error:%d drift:%d count:%d k:%d",
+            v, state->bias, state->error_sum, state->drift, state->count, k);
+
+#if 0 // JPEG LS
+    if (k == 0 && 2 * state->drift <= -state->count)
+        v ^= (-1);
+#else
+    v ^= ((2 * state->drift + state->count) >> 31);
+#endif
+
+    ret = fold(v + state->bias, bits);
+
+    update_vlc_state(state, v);
+
+    return ret;
+}
+
+static av_always_inline void decode_line(FFV1Context *s, int w,
+                                         int16_t *sample[2],
+                                         int plane_index, int bits)
+{
+    PlaneContext *const p = &s->plane[plane_index];
+    RangeCoder *const c   = &s->c;
+    int x;
+    int run_count = 0;
+    int run_mode  = 0;
+    int run_index = s->run_index;
+
+    for (x = 0; x < w; x++) {
+        int diff, context, sign;
+
+        context = get_context(p, sample[1] + x, sample[0] + x, sample[1] + x);
+        if (context < 0) {
+            context = -context;
+            sign    = 1;
+        } else
+            sign = 0;
+
+        av_assert2(context < p->context_count);
+
+        if (s->ac) {
+            diff = get_symbol_inline(c, p->state[context], 1);
+        } else {
+            if (context == 0 && run_mode == 0)
+                run_mode = 1;
+
+            if (run_mode) {
+                if (run_count == 0 && run_mode == 1) {
+                    if (get_bits1(&s->gb)) {
+                        run_count = 1 << ff_log2_run[run_index];
+                        if (x + run_count <= w)
+                            run_index++;
+                    } else {
+                        if (ff_log2_run[run_index])
+                            run_count = get_bits(&s->gb, ff_log2_run[run_index]);
+                        else
+                            run_count = 0;
+                        if (run_index)
+                            run_index--;
+                        run_mode = 2;
+                    }
+                }
+                run_count--;
+                if (run_count < 0) {
+                    run_mode  = 0;
+                    run_count = 0;
+                    diff      = get_vlc_symbol(&s->gb, &p->vlc_state[context],
+                                               bits);
+                    if (diff >= 0)
+                        diff++;
+                } else
+                    diff = 0;
+            } else
+                diff = get_vlc_symbol(&s->gb, &p->vlc_state[context], bits);
+
+            av_dlog(s->avctx, "count:%d index:%d, mode:%d, x:%d pos:%d\n",
+                    run_count, run_index, run_mode, x, get_bits_count(&s->gb));
+        }
+
+        if (sign)
+            diff = -diff;
+
+        sample[1][x] = (predict(sample[1] + x, sample[0] + x) + diff) &
+                       ((1 << bits) - 1);
+    }
+    s->run_index = run_index;
+}
+
+static void decode_plane(FFV1Context *s, uint8_t *src,
+                         int w, int h, int stride, int plane_index)
+{
+    int x, y;
+    int16_t *sample[2];
+    sample[0] = s->sample_buffer + 3;
+    sample[1] = s->sample_buffer + w + 6 + 3;
+
+    s->run_index = 0;
+
+    memset(s->sample_buffer, 0, 2 * (w + 6) * sizeof(*s->sample_buffer));
+
+    for (y = 0; y < h; y++) {
+        int16_t *temp = sample[0]; // FIXME: try a normal buffer
+
+        sample[0] = sample[1];
+        sample[1] = temp;
+
+        sample[1][-1] = sample[0][0];
+        sample[0][w]  = sample[0][w - 1];
+
+// { START_TIMER
+        if (s->avctx->bits_per_raw_sample <= 8) {
+            decode_line(s, w, sample, plane_index, 8);
+            for (x = 0; x < w; x++)
+                src[x + stride * y] = sample[1][x];
+        } else {
+            decode_line(s, w, sample, plane_index, s->avctx->bits_per_raw_sample);
+            if (s->packed_at_lsb) {
+                for (x = 0; x < w; x++) {
+                    ((uint16_t*)(src + stride*y))[x] = sample[1][x];
+                }
+            } else {
+                for (x = 0; x < w; x++) {
+                    ((uint16_t*)(src + stride*y))[x] = sample[1][x] << (16 - s->avctx->bits_per_raw_sample);
+                }
+            }
+        }
+// STOP_TIMER("decode-line") }
+    }
+}
+
+static void decode_rgb_frame(FFV1Context *s, uint8_t *src[3], int w, int h, int stride[3])
+{
+    int x, y, p;
+    int16_t *sample[4][2];
+    int lbd  = s->avctx->bits_per_raw_sample <= 8;
+    int bits = s->avctx->bits_per_raw_sample > 0 ? s->avctx->bits_per_raw_sample : 8;
+    int offset = 1 << bits;
+    for (x = 0; x < 4; x++) {
+        sample[x][0] = s->sample_buffer +  x * 2      * (w + 6) + 3;
+        sample[x][1] = s->sample_buffer + (x * 2 + 1) * (w + 6) + 3;
+    }
+
+    s->run_index = 0;
+
+    memset(s->sample_buffer, 0, 8*(w+6)*sizeof(*s->sample_buffer));
+
+    for (y = 0; y < h; y++) {
+        for (p = 0; p < 3 + s->transparency; p++) {
+            int16_t *temp = sample[p][0]; // FIXME: try a normal buffer
+
+            sample[p][0] = sample[p][1];
+            sample[p][1] = temp;
+
+            sample[p][1][-1]= sample[p][0][0  ];
+            sample[p][0][ w]= sample[p][0][w-1];
+            if (lbd)
+                decode_line(s, w, sample[p], (p+1)/2, 9);
+            else
+                decode_line(s, w, sample[p], (p+1)/2, bits+1);
+        }
+        for (x = 0; x < w; x++) {
+            int g = sample[0][1][x];
+            int b = sample[1][1][x];
+            int r = sample[2][1][x];
+            int a = sample[3][1][x];
+
+            b -= offset;
+            r -= offset;
+            g -= (b + r) >> 2;
+            b += g;
+            r += g;
+
+            if (lbd)
+                *((uint32_t*)(src[0] + x*4 + stride[0]*y)) = b + (g<<8) + (r<<16) + (a<<24);
+            else {
+                *((uint16_t*)(src[0] + x*2 + stride[0]*y)) = b;
+                *((uint16_t*)(src[1] + x*2 + stride[1]*y)) = g;
+                *((uint16_t*)(src[2] + x*2 + stride[2]*y)) = r;
+            }
+        }
+    }
+}
+
+static int decode_slice_header(FFV1Context *f, FFV1Context *fs)
+{
+    RangeCoder *c = &fs->c;
+    uint8_t state[CONTEXT_SIZE];
+    unsigned ps, i, context_count;
+    memset(state, 128, sizeof(state));
+
+    av_assert0(f->version > 2);
+
+    fs->slice_x      =  get_symbol(c, state, 0)      * f->width ;
+    fs->slice_y      =  get_symbol(c, state, 0)      * f->height;
+    fs->slice_width  = (get_symbol(c, state, 0) + 1) * f->width  + fs->slice_x;
+    fs->slice_height = (get_symbol(c, state, 0) + 1) * f->height + fs->slice_y;
+
+    fs->slice_x /= f->num_h_slices;
+    fs->slice_y /= f->num_v_slices;
+    fs->slice_width  = fs->slice_width /f->num_h_slices - fs->slice_x;
+    fs->slice_height = fs->slice_height/f->num_v_slices - fs->slice_y;
+    if ((unsigned)fs->slice_width > f->width || (unsigned)fs->slice_height > f->height)
+        return -1;
+    if (    (unsigned)fs->slice_x + (uint64_t)fs->slice_width  > f->width
+         || (unsigned)fs->slice_y + (uint64_t)fs->slice_height > f->height)
+        return -1;
+
+    for (i = 0; i < f->plane_count; i++) {
+        PlaneContext * const p = &fs->plane[i];
+        int idx = get_symbol(c, state, 0);
+        if (idx > (unsigned)f->quant_table_count) {
+            av_log(f->avctx, AV_LOG_ERROR, "quant_table_index out of range\n");
+            return -1;
+        }
+        p->quant_table_index = idx;
+        memcpy(p->quant_table, f->quant_tables[idx], sizeof(p->quant_table));
+        context_count = f->context_count[idx];
+
+        if (p->context_count < context_count) {
+            av_freep(&p->state);
+            av_freep(&p->vlc_state);
+        }
+        p->context_count = context_count;
+    }
+
+    ps = get_symbol(c, state, 0);
+    if (ps == 1) {
+        f->picture.interlaced_frame = 1;
+        f->picture.top_field_first  = 1;
+    } else if (ps == 2) {
+        f->picture.interlaced_frame = 1;
+        f->picture.top_field_first  = 0;
+    } else if (ps == 3) {
+        f->picture.interlaced_frame = 0;
+    }
+    f->picture.sample_aspect_ratio.num = get_symbol(c, state, 0);
+    f->picture.sample_aspect_ratio.den = get_symbol(c, state, 0);
+
+    return 0;
+}
+
+static int decode_slice(AVCodecContext *c, void *arg)
+{
+    FFV1Context *fs  = *(void **)arg;
+    FFV1Context *f   = fs->avctx->priv_data;
+    int width, height, x, y;
+    const int ps      = av_pix_fmt_desc_get(c->pix_fmt)->comp[0].step_minus1 + 1;
+    AVFrame * const p = &f->picture;
+
+    if (f->version > 2) {
+        if (ffv1_init_slice_state(f, fs) < 0)
+            return AVERROR(ENOMEM);
+        if (decode_slice_header(f, fs) < 0) {
+            fs->slice_damaged = 1;
+            return AVERROR_INVALIDDATA;
+        }
+    }
+    if (ffv1_init_slice_state(f, fs) < 0)
+        return AVERROR(ENOMEM);
+    if (f->picture.key_frame)
+        ffv1_clear_slice_state(f, fs);
+    width = fs->slice_width;
+    height= fs->slice_height;
+    x= fs->slice_x;
+    y= fs->slice_y;
+
+    if (!fs->ac) {
+        if (f->version == 3 && f->minor_version > 1 || f->version > 3)
+            get_rac(&fs->c, (uint8_t[]) {129});
+        fs->ac_byte_count = f->version > 2 || (!x&&!y) ? fs->c.bytestream - fs->c.bytestream_start - 1 : 0;
+        init_get_bits(&fs->gb,
+                      fs->c.bytestream_start + fs->ac_byte_count,
+                      (fs->c.bytestream_end - fs->c.bytestream_start - fs->ac_byte_count) * 8);
+    }
+
+    av_assert1(width && height);
+    if (f->colorspace == 0) {
+        const int chroma_width  = -((-width)  >> f->chroma_h_shift);
+        const int chroma_height = -((-height) >> f->chroma_v_shift);
+        const int cx            = x >> f->chroma_h_shift;
+        const int cy            = y >> f->chroma_v_shift;
+        decode_plane(fs, p->data[0] + ps*x + y*p->linesize[0], width, height, p->linesize[0], 0);
+
+        if (f->chroma_planes) {
+            decode_plane(fs, p->data[1] + ps*cx+cy*p->linesize[1], chroma_width, chroma_height, p->linesize[1], 1);
+            decode_plane(fs, p->data[2] + ps*cx+cy*p->linesize[2], chroma_width, chroma_height, p->linesize[2], 1);
+        }
+        if (fs->transparency)
+            decode_plane(fs, p->data[3] + ps*x + y*p->linesize[3], width, height, p->linesize[3], 2);
+    } else {
+        uint8_t *planes[3] = {p->data[0] + ps*x + y*p->linesize[0],
+                              p->data[1] + ps*x + y*p->linesize[1],
+                              p->data[2] + ps*x + y*p->linesize[2]};
+        decode_rgb_frame(fs, planes, width, height, p->linesize);
+    }
+    if (fs->ac && f->version > 2) {
+        int v;
+        get_rac(&fs->c, (uint8_t[]) {129});
+        v = fs->c.bytestream_end - fs->c.bytestream - 2 - 5*f->ec;
+        if (v) {
+            av_log(f->avctx, AV_LOG_ERROR, "bytestream end mismatching by %d\n", v);
+            fs->slice_damaged = 1;
+        }
+    }
+
+    emms_c();
+
+    return 0;
+}
+
+static int read_quant_table(RangeCoder *c, int16_t *quant_table, int scale)
+{
+    int v;
+    int i = 0;
+    uint8_t state[CONTEXT_SIZE];
+
+    memset(state, 128, sizeof(state));
+
+    for (v = 0; i < 128; v++) {
+        unsigned len = get_symbol(c, state, 0) + 1;
+
+        if (len > 128 - i)
+            return -1;
+
+        while (len--) {
+            quant_table[i] = scale * v;
+            i++;
+        }
+    }
+
+    for (i = 1; i < 128; i++)
+        quant_table[256 - i] = -quant_table[i];
+    quant_table[128] = -quant_table[127];
+
+    return 2 * v - 1;
+}
+
+static int read_quant_tables(RangeCoder *c,
+                             int16_t quant_table[MAX_CONTEXT_INPUTS][256])
+{
+    int i;
+    int context_count = 1;
+
+    for (i = 0; i < 5; i++) {
+        context_count *= read_quant_table(c, quant_table[i], context_count);
+        if (context_count > 32768U) {
+            return -1;
+        }
+    }
+    return (context_count + 1) / 2;
+}
+
+static int read_extra_header(FFV1Context *f)
+{
+    RangeCoder *const c = &f->c;
+    uint8_t state[CONTEXT_SIZE];
+    int i, j, k;
+    uint8_t state2[32][CONTEXT_SIZE];
+
+    memset(state2, 128, sizeof(state2));
+    memset(state, 128, sizeof(state));
+
+    ff_init_range_decoder(c, f->avctx->extradata, f->avctx->extradata_size);
+    ff_build_rac_states(c, 0.05 * (1LL << 32), 256 - 8);
+
+    f->version = get_symbol(c, state, 0);
+    if (f->version > 2) {
+        c->bytestream_end -= 4;
+        f->minor_version = get_symbol(c, state, 0);
+    }
+    f->ac = f->avctx->coder_type = get_symbol(c, state, 0);
+    if (f->ac > 1)
+        for (i = 1; i < 256; i++)
+            f->state_transition[i] = get_symbol(c, state, 1) + c->one_state[i];
+
+    f->colorspace                 = get_symbol(c, state, 0); // YUV cs type
+    f->avctx->bits_per_raw_sample = get_symbol(c, state, 0);
+    f->chroma_planes  = get_rac(c, state);
+    f->chroma_h_shift = get_symbol(c, state, 0);
+    f->chroma_v_shift = get_symbol(c, state, 0);
+    f->transparency = get_rac(c, state);
+    f->plane_count  = 2 + f->transparency;
+    f->num_h_slices = 1 + get_symbol(c, state, 0);
+    f->num_v_slices = 1 + get_symbol(c, state, 0);
+
+    if (f->num_h_slices > (unsigned)f->width ||
+        f->num_v_slices > (unsigned)f->height) {
+        av_log(f->avctx, AV_LOG_ERROR, "too many slices\n");
+        return -1;
+    }
+
+    f->quant_table_count = get_symbol(c, state, 0);
+
+    if (f->quant_table_count > (unsigned)MAX_QUANT_TABLES)
+        return -1;
+
+    for (i = 0; i < f->quant_table_count; i++) {
+        f->context_count[i] = read_quant_tables(c, f->quant_tables[i]);
+        if (f->context_count[i] < 0) {
+            av_log(f->avctx, AV_LOG_ERROR, "read_quant_table error\n");
+            return -1;
+        }
+    }
+
+    if (ffv1_allocate_initial_states(f) < 0)
+        return AVERROR(ENOMEM);
+
+    for (i = 0; i < f->quant_table_count; i++)
+        if (get_rac(c, state))
+            for (j = 0; j < f->context_count[i]; j++)
+                for (k = 0; k < CONTEXT_SIZE; k++) {
+                    int pred = j ? f->initial_states[i][j - 1][k] : 128;
+                    f->initial_states[i][j][k] =
+                        (pred + get_symbol(c, state2[k], 1)) & 0xFF;
+                }
+
+    if (f->version > 2) {
+        f->ec = get_symbol(c, state, 0);
+    }
+
+    if (f->version > 2) {
+        unsigned v;
+        v = av_crc(av_crc_get_table(AV_CRC_32_IEEE), 0, f->avctx->extradata, f->avctx->extradata_size);
+        if (v) {
+            av_log(f->avctx, AV_LOG_ERROR, "CRC mismatch %X!\n", v);
+            return AVERROR_INVALIDDATA;
+        }
+    }
+
+    return 0;
+}
+
+static int read_header(FFV1Context *f)
+{
+    uint8_t state[CONTEXT_SIZE];
+    int i, j, context_count = -1; //-1 to avoid warning
+    RangeCoder *const c = &f->slice_context[0]->c;
+
+    memset(state, 128, sizeof(state));
+
+    if (f->version < 2) {
+        unsigned v= get_symbol(c, state, 0);
+        if (v >= 2) {
+            av_log(f->avctx, AV_LOG_ERROR, "invalid version %d in ver01 header\n", v);
+            return AVERROR_INVALIDDATA;
+        }
+        f->version = v;
+        f->ac      = f->avctx->coder_type = get_symbol(c, state, 0);
+        if (f->ac > 1)
+            for (i = 1; i < 256; i++)
+                f->state_transition[i] = get_symbol(c, state, 1) + c->one_state[i];
+        f->colorspace = get_symbol(c, state, 0); // YUV cs type
+        if (f->version > 0)
+            f->avctx->bits_per_raw_sample = get_symbol(c, state, 0);
+        f->chroma_planes  = get_rac(c, state);
+        f->chroma_h_shift = get_symbol(c, state, 0);
+        f->chroma_v_shift = get_symbol(c, state, 0);
+        f->transparency   = get_rac(c, state);
+        f->plane_count    = 2 + f->transparency;
+    }
+
+    if (f->colorspace == 0) {
+        if (!f->transparency && !f->chroma_planes) {
+            if (f->avctx->bits_per_raw_sample <= 8)
+                f->avctx->pix_fmt = AV_PIX_FMT_GRAY8;
+            else
+                f->avctx->pix_fmt = AV_PIX_FMT_GRAY16;
+        } else if (f->avctx->bits_per_raw_sample<=8 && !f->transparency) {
+            switch(16 * f->chroma_h_shift + f->chroma_v_shift) {
+            case 0x00: f->avctx->pix_fmt = AV_PIX_FMT_YUV444P; break;
+            case 0x01: f->avctx->pix_fmt = AV_PIX_FMT_YUV440P; break;
+            case 0x10: f->avctx->pix_fmt = AV_PIX_FMT_YUV422P; break;
+            case 0x11: f->avctx->pix_fmt = AV_PIX_FMT_YUV420P; break;
+            case 0x20: f->avctx->pix_fmt = AV_PIX_FMT_YUV411P; break;
+            case 0x22: f->avctx->pix_fmt = AV_PIX_FMT_YUV410P; break;
+            default:
+                av_log(f->avctx, AV_LOG_ERROR, "format not supported\n");
+                return -1;
+            }
+        } else if (f->avctx->bits_per_raw_sample <= 8 && f->transparency) {
+            switch(16*f->chroma_h_shift + f->chroma_v_shift) {
+            case 0x00: f->avctx->pix_fmt = AV_PIX_FMT_YUVA444P; break;
+            case 0x10: f->avctx->pix_fmt = AV_PIX_FMT_YUVA422P; break;
+            case 0x11: f->avctx->pix_fmt = AV_PIX_FMT_YUVA420P; break;
+            default:
+                av_log(f->avctx, AV_LOG_ERROR, "format not supported\n");
+                return -1;
+            }
+        } else if (f->avctx->bits_per_raw_sample == 9) {
+            f->packed_at_lsb = 1;
+            switch(16 * f->chroma_h_shift + f->chroma_v_shift) {
+            case 0x00: f->avctx->pix_fmt = AV_PIX_FMT_YUV444P9; break;
+            case 0x10: f->avctx->pix_fmt = AV_PIX_FMT_YUV422P9; break;
+            case 0x11: f->avctx->pix_fmt = AV_PIX_FMT_YUV420P9; break;
+            default:
+                av_log(f->avctx, AV_LOG_ERROR, "format not supported\n");
+                return -1;
+            }
+        } else if (f->avctx->bits_per_raw_sample == 10) {
+            f->packed_at_lsb = 1;
+            switch(16 * f->chroma_h_shift + f->chroma_v_shift) {
+            case 0x00: f->avctx->pix_fmt = AV_PIX_FMT_YUV444P10; break;
+            case 0x10: f->avctx->pix_fmt = AV_PIX_FMT_YUV422P10; break;
+            case 0x11: f->avctx->pix_fmt = AV_PIX_FMT_YUV420P10; break;
+            default:
+                av_log(f->avctx, AV_LOG_ERROR, "format not supported\n");
+                return -1;
+            }
+        } else {
+            switch(16 * f->chroma_h_shift + f->chroma_v_shift) {
+            case 0x00: f->avctx->pix_fmt = AV_PIX_FMT_YUV444P16; break;
+            case 0x10: f->avctx->pix_fmt = AV_PIX_FMT_YUV422P16; break;
+            case 0x11: f->avctx->pix_fmt = AV_PIX_FMT_YUV420P16; break;
+            default:
+                av_log(f->avctx, AV_LOG_ERROR, "format not supported\n");
+                return -1;
+            }
+        }
+    } else if (f->colorspace == 1) {
+        if (f->chroma_h_shift || f->chroma_v_shift) {
+            av_log(f->avctx, AV_LOG_ERROR,
+                   "chroma subsampling not supported in this colorspace\n");
+            return -1;
+        }
+        if (     f->avctx->bits_per_raw_sample ==  9)
+            f->avctx->pix_fmt = AV_PIX_FMT_GBRP9;
+        else if (f->avctx->bits_per_raw_sample == 10)
+            f->avctx->pix_fmt = AV_PIX_FMT_GBRP10;
+        else if (f->avctx->bits_per_raw_sample == 12)
+            f->avctx->pix_fmt = AV_PIX_FMT_GBRP12;
+        else if (f->avctx->bits_per_raw_sample == 14)
+            f->avctx->pix_fmt = AV_PIX_FMT_GBRP14;
+        else
+        if (f->transparency) f->avctx->pix_fmt = AV_PIX_FMT_RGB32;
+        else                 f->avctx->pix_fmt = AV_PIX_FMT_0RGB32;
+    } else {
+        av_log(f->avctx, AV_LOG_ERROR, "colorspace not supported\n");
+        return -1;
+    }
+
+    av_dlog(f->avctx, "%d %d %d\n",
+            f->chroma_h_shift, f->chroma_v_shift, f->avctx->pix_fmt);
+
+    if (f->version < 2) {
+        context_count = read_quant_tables(c, f->quant_table);
+        if (context_count < 0) {
+            av_log(f->avctx, AV_LOG_ERROR, "read_quant_table error\n");
+            return -1;
+        }
+    } else if (f->version < 3) {
+        f->slice_count = get_symbol(c, state, 0);
+    } else {
+        const uint8_t *p = c->bytestream_end;
+        for (f->slice_count = 0; f->slice_count < MAX_SLICES && 3 < p - c->bytestream_start; f->slice_count++) {
+            int trailer = 3 + 5*!!f->ec;
+            int size = AV_RB24(p-trailer);
+            if (size + trailer > p - c->bytestream_start)
+                break;
+            p -= size + trailer;
+        }
+    }
+    if (f->slice_count > (unsigned)MAX_SLICES || f->slice_count <= 0) {
+        av_log(f->avctx, AV_LOG_ERROR, "slice count %d is invalid\n", f->slice_count);
+        return -1;
+    }
+
+    for (j = 0; j < f->slice_count; j++) {
+        FFV1Context *fs = f->slice_context[j];
+        fs->ac = f->ac;
+        fs->packed_at_lsb = f->packed_at_lsb;
+
+        fs->slice_damaged = 0;
+
+        if (f->version == 2) {
+            fs->slice_x      =  get_symbol(c, state, 0)      * f->width ;
+            fs->slice_y      =  get_symbol(c, state, 0)      * f->height;
+            fs->slice_width  = (get_symbol(c, state, 0) + 1) * f->width  + fs->slice_x;
+            fs->slice_height = (get_symbol(c, state, 0) + 1) * f->height + fs->slice_y;
+
+            fs->slice_x     /= f->num_h_slices;
+            fs->slice_y     /= f->num_v_slices;
+            fs->slice_width  = fs->slice_width  / f->num_h_slices - fs->slice_x;
+            fs->slice_height = fs->slice_height / f->num_v_slices - fs->slice_y;
+            if ((unsigned)fs->slice_width  > f->width ||
+                (unsigned)fs->slice_height > f->height)
+                return -1;
+            if ((unsigned)fs->slice_x + (uint64_t)fs->slice_width  > f->width ||
+                (unsigned)fs->slice_y + (uint64_t)fs->slice_height > f->height)
+                return -1;
+        }
+
+        for (i = 0; i < f->plane_count; i++) {
+            PlaneContext *const p = &fs->plane[i];
+
+            if (f->version == 2) {
+                int idx = get_symbol(c, state, 0);
+                if (idx > (unsigned)f->quant_table_count) {
+                    av_log(f->avctx, AV_LOG_ERROR,
+                           "quant_table_index out of range\n");
+                    return -1;
+                }
+                p->quant_table_index = idx;
+                memcpy(p->quant_table, f->quant_tables[idx],
+                       sizeof(p->quant_table));
+                context_count = f->context_count[idx];
+            } else {
+                memcpy(p->quant_table, f->quant_table, sizeof(p->quant_table));
+            }
+
+            if (f->version <= 2) {
+                av_assert0(context_count >= 0);
+                if (p->context_count < context_count) {
+                    av_freep(&p->state);
+                    av_freep(&p->vlc_state);
+                }
+                p->context_count = context_count;
+            }
+        }
+    }
+    return 0;
+}
+
+static av_cold int decode_init(AVCodecContext *avctx)
+{
+    FFV1Context *f = avctx->priv_data;
+
+    ffv1_common_init(avctx);
+
+    if (avctx->extradata && read_extra_header(f) < 0)
+        return -1;
+
+    if (ffv1_init_slice_contexts(f) < 0)
+        return -1;
+
+    return 0;
+}
+
+static int decode_frame(AVCodecContext *avctx, void *data, int *data_size, AVPacket *avpkt)
+{
+    const uint8_t *buf  = avpkt->data;
+    int buf_size        = avpkt->size;
+    FFV1Context *f      = avctx->priv_data;
+    RangeCoder *const c = &f->slice_context[0]->c;
+    AVFrame *const p    = &f->picture;
+    int i;
+    uint8_t keystate = 128;
+    const uint8_t *buf_p;
+
+    AVFrame *picture = data;
+
+    /* release previously stored data */
+    if (p->data[0])
+        avctx->release_buffer(avctx, p);
+
+    ff_init_range_decoder(c, buf, buf_size);
+    ff_build_rac_states(c, 0.05 * (1LL << 32), 256 - 8);
+
+    p->pict_type = AV_PICTURE_TYPE_I; // FIXME: I vs. P
+    if (get_rac(c, &keystate)) {
+        p->key_frame = 1;
+        f->key_frame_ok = 0;
+        if (read_header(f) < 0)
+            return -1;
+        f->key_frame_ok = 1;
+    } else {
+        if (!f->key_frame_ok) {
+            av_log(avctx, AV_LOG_ERROR, "Cant decode non keyframe without valid keyframe\n");
+            return AVERROR_INVALIDDATA;
+        }
+        p->key_frame= 0;
+    }
+
+    p->reference = 3; //for error concealment
+    if (avctx->get_buffer(avctx, p) < 0) {
+        av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
+        return -1;
+    }
+
+    if (avctx->debug&FF_DEBUG_PICT_INFO)
+        av_log(avctx, AV_LOG_DEBUG, "ver:%d keyframe:%d coder:%d ec:%d slices:%d bps:%d\n",
+               f->version, p->key_frame, f->ac, f->ec, f->slice_count, f->avctx->bits_per_raw_sample);
+
+    buf_p = buf + buf_size;
+    for (i = f->slice_count - 1; i >= 0; i--) {
+        FFV1Context *fs = f->slice_context[i];
+        int trailer = 3 + 5*!!f->ec;
+        int v;
+
+        if (i || f->version>2) v = AV_RB24(buf_p-trailer)+trailer;
+        else                   v = buf_p - c->bytestream_start;
+        if (buf_p - c->bytestream_start < v) {
+            av_log(avctx, AV_LOG_ERROR, "Slice pointer chain broken\n");
+            return -1;
+        }
+        buf_p -= v;
+
+        if (f->ec) {
+            unsigned crc = av_crc(av_crc_get_table(AV_CRC_32_IEEE), 0, buf_p, v);
+            if (crc) {
+                int64_t ts = avpkt->pts != AV_NOPTS_VALUE ? avpkt->pts : avpkt->dts;
+                av_log(f->avctx, AV_LOG_ERROR, "CRC mismatch %X!", crc);
+                if (ts != AV_NOPTS_VALUE && avctx->pkt_timebase.num) {
+                    av_log(f->avctx, AV_LOG_ERROR, "at %f seconds\n", ts*av_q2d(avctx->pkt_timebase));
+                } else if (ts != AV_NOPTS_VALUE) {
+                    av_log(f->avctx, AV_LOG_ERROR, "at %"PRId64"\n", ts);
+                } else {
+                    av_log(f->avctx, AV_LOG_ERROR, "\n");
+                }
+                fs->slice_damaged = 1;
+            }
+        }
+
+        if (i) {
+            ff_init_range_decoder(&fs->c, buf_p, v);
+        } else
+            fs->c.bytestream_end = (uint8_t *)(buf_p + v);
+    }
+
+    avctx->execute(avctx, decode_slice, &f->slice_context[0], NULL, f->slice_count, sizeof(void*));
+
+    for (i=f->slice_count-1; i>=0; i--) {
+        FFV1Context *fs= f->slice_context[i];
+        int j;
+        if (fs->slice_damaged && f->last_picture.data[0]) {
+            uint8_t *dst[4], *src[4];
+            for (j=0; j<4; j++) {
+                int sh = (j==1 || j==2) ? f->chroma_h_shift : 0;
+                int sv = (j==1 || j==2) ? f->chroma_v_shift : 0;
+                dst[j] = f->picture     .data[j] + f->picture     .linesize[j]*
+                         (fs->slice_y>>sv) + (fs->slice_x>>sh);
+                src[j] = f->last_picture.data[j] + f->last_picture.linesize[j]*
+                         (fs->slice_y>>sv) + (fs->slice_x>>sh);
+            }
+            av_image_copy(dst, f->picture.linesize, (const uint8_t **)src, f->last_picture.linesize,
+                          avctx->pix_fmt, fs->slice_width, fs->slice_height);
+        }
+    }
+
+    f->picture_number++;
+
+    *picture   = *p;
+    *data_size = sizeof(AVFrame);
+
+    FFSWAP(AVFrame, f->picture, f->last_picture);
+
+    return buf_size;
+}
+
+AVCodec ff_ffv1_decoder = {
+    .name           = "ffv1",
+    .type           = AVMEDIA_TYPE_VIDEO,
+    .id             = AV_CODEC_ID_FFV1,
+    .priv_data_size = sizeof(FFV1Context),
+    .init           = decode_init,
+    .close          = ffv1_common_end,
+    .decode         = decode_frame,
+    .capabilities   = CODEC_CAP_DR1 /*| CODEC_CAP_DRAW_HORIZ_BAND*/ |
+                      CODEC_CAP_SLICE_THREADS,
+    .long_name      = NULL_IF_CONFIG_SMALL("FFmpeg video codec #1"),
+};