ffv1: split decoder and encoder

1 files changed, 184 insertions, 0 deletions

diff --git a/libavcodec/ffv1.h b/libavcodec/ffv1.h
new file mode 100644
index 0000000000..7676c61be3
--- /dev/null
+++ b/libavcodec/ffv1.h
@@ -0,0 +1,184 @@
+/*
+ * FFV1 codec for libavcodec
+ *
+ * Copyright (c) 2012 Michael Niedermayer <michaelni@gmx.at>
+ *
+ * This file is part of Libav.
+ *
+ * Libav 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.
+ *
+ * Libav 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 Libav; 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
+#include "avcodec.h"
+
+#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];
+
+extern const int8_t ffv1_quant5_10bit[256];
+extern const int8_t ffv1_quant5[256];
+extern const int8_t ffv1_quant9_10bit[256];
+extern const int8_t ffv1_quant11[256];
+extern const uint8_t ffv1_ver2_state[256];
+
+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 {
+    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 width, height;
+    int chroma_h_shift, chroma_v_shift;
+    int flags;
+    int picture_number;
+    AVFrame picture;
+    int plane_count;
+    int ac;     // 1 = range coder <-> 0 = golomb rice
+    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 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;
+} FFV1Context;
+
+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;
+}
+
+int ffv1_common_init(AVCodecContext *avctx);
+int ffv1_init_slice_state(FFV1Context *f);
+int ffv1_init_slice_contexts(FFV1Context *f);
+int ffv1_allocate_initial_states(FFV1Context *f);
+void ffv1_clear_state(FFV1Context *f);
+int ffv1_close(AVCodecContext *avctx);
+
+#endif /* AVCODEC_FFV1_H */