avcodec/ffv1: split off and share frame header parsing code

Signed-off-by: James Almer <[email protected]>

Author: jamrial

libavcodec/Makefile

@@ -369,8 +369,8 @@ OBJS-$(CONFIG_EVRC_DECODER)            += evrcdec.o acelp_vectors.o lsp.o
 OBJS-$(CONFIG_EXR_DECODER)             += exr.o exrdsp.o half2float.o
 OBJS-$(CONFIG_EXR_ENCODER)             += exrenc.o float2half.o
 OBJS-$(CONFIG_FASTAUDIO_DECODER)       += fastaudio.o
-OBJS-$(CONFIG_FFV1_DECODER)            += ffv1dec.o ffv1.o
-OBJS-$(CONFIG_FFV1_ENCODER)            += ffv1enc.o ffv1.o
+OBJS-$(CONFIG_FFV1_DECODER)            += ffv1dec.o ffv1_parse.o ffv1.o
+OBJS-$(CONFIG_FFV1_ENCODER)            += ffv1enc.o ffv1_parse.o ffv1.o
 OBJS-$(CONFIG_FFV1_VULKAN_ENCODER)     += ffv1enc.o ffv1.o ffv1enc_vulkan.o
 OBJS-$(CONFIG_FFWAVESYNTH_DECODER)     += ffwavesynth.o
 OBJS-$(CONFIG_FIC_DECODER)             += fic.o

libavcodec/ffv1.c

@@ -33,10 +33,8 @@
 #include "ffv1.h"
 #include "libavutil/refstruct.h"
 
-av_cold int ff_ffv1_common_init(AVCodecContext *avctx)
+av_cold int ff_ffv1_common_init(AVCodecContext *avctx, FFV1Context *s)
 {
-    FFV1Context *s = avctx->priv_data;
-
     if (!avctx->width || !avctx->height)
         return AVERROR_INVALIDDATA;
 
@@ -221,10 +219,13 @@ void ff_ffv1_clear_slice_state(const FFV1Context *f, FFV1SliceContext *sc)
     }
 }
 
+int ff_ffv1_get_symbol(RangeCoder *c, uint8_t *state, int is_signed)
+{
+    return get_symbol_inline(c, state, is_signed);
+}
 
-av_cold int ff_ffv1_close(AVCodecContext *avctx)
+av_cold void ff_ffv1_close(FFV1Context *s)
 {
-    FFV1Context *s = avctx->priv_data;
     int i, j;
 
     for (j = 0; j < s->max_slice_count; j++) {
@@ -238,7 +239,6 @@ av_cold int ff_ffv1_close(AVCodecContext *avctx)
 
     av_refstruct_unref(&s->slice_damaged);
 
-    av_freep(&avctx->stats_out);
     for (j = 0; j < s->quant_table_count; j++) {
         av_freep(&s->initial_states[j]);
         for (i = 0; i < s->max_slice_count; i++) {
@@ -249,6 +249,4 @@ av_cold int ff_ffv1_close(AVCodecContext *avctx)
     }
 
     av_freep(&s->slices);
-
-    return 0;
 }

libavcodec/ffv1.h

@@ -28,6 +28,7 @@
  * FF Video Codec 1 (a lossless codec)
  */
 
+#include "libavutil/attributes.h"
 #include "avcodec.h"
 #include "get_bits.h"
 #include "mathops.h"
@@ -169,15 +170,20 @@ typedef struct FFV1Context {
     uint8_t           frame_damaged;
 } FFV1Context;
 
-int ff_ffv1_common_init(AVCodecContext *avctx);
+int ff_ffv1_common_init(AVCodecContext *avctx, FFV1Context *s);
 int ff_ffv1_init_slice_state(const FFV1Context *f, FFV1SliceContext *sc);
 int ff_ffv1_init_slices_state(FFV1Context *f);
 int ff_ffv1_init_slice_contexts(FFV1Context *f);
 PlaneContext *ff_ffv1_planes_alloc(void);
 int ff_ffv1_allocate_initial_states(FFV1Context *f);
 void ff_ffv1_clear_slice_state(const FFV1Context *f, FFV1SliceContext *sc);
-int ff_ffv1_close(AVCodecContext *avctx);
+void ff_ffv1_close(FFV1Context *s);
 int ff_need_new_slices(int width, int num_h_slices, int chroma_shift);
+int ff_ffv1_parse_header(FFV1Context *f, RangeCoder *c, uint8_t *state);
+int ff_ffv1_read_extra_header(FFV1Context *f);
+int ff_ffv1_read_quant_tables(RangeCoder *c,
+                              int16_t quant_table[MAX_CONTEXT_INPUTS][256]);
+int ff_ffv1_get_symbol(RangeCoder *c, uint8_t *state, int is_signed);
 
 /**
  * This is intended for both width and height
@@ -223,4 +229,29 @@ static inline void update_vlc_state(VlcState *const state, const int v)
     state->count = count;
 }
 
+
+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 e;
+        unsigned a;
+        e = 0;
+        while (get_rac(c, state + 1 + FFMIN(e, 9))) { // 1..10
+            e++;
+            if (e > 31)
+                return AVERROR_INVALIDDATA;
+        }
+
+        a = 1;
+        for (int 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;
+    }
+}
+
 #endif /* AVCODEC_FFV1_H */