lavc: Move context_model to codec private options

This option is only used by ffv1 and ffvhuff.
It is a very codec-specific option, so deprecate the global variant.
Improve documentation a little.
Signed-off-by: Vittorio Giovara <vittorio.giovara@gmail.com>

libavcodec/avcodec.h

@@ -2341,12 +2341,11 @@ typedef struct AVCodecContext {
     int coder_type;
 #endif /* FF_API_CODER_TYPE */
 
-    /**
-     * context model
-     * - encoding: Set by user.
-     * - decoding: unused
-     */
+#if FF_API_PRIVATE_OPT
+    /** @deprecated use encoder private options instead */
+    attribute_deprecated
     int context_model;
+#endif
 
 #if FF_API_MPV_OPT
     /**

libavcodec/ffv1.h

@@ -103,6 +103,7 @@ typedef struct FFV1Context {
     int ec;
     int slice_damaged;
     int key_frame_ok;
+    int context_model;
 
     int bits_per_raw_sample;
     int packed_at_lsb;

libavcodec/ffv1enc.c

@@ -261,7 +261,7 @@ static void encode_plane(FFV1Context *s, uint8_t *src, int w, int h,
                          int stride, int plane_index)
 {
     int x, y, i;
-    const int ring_size = s->avctx->context_model ? 3 : 2;
+    const int ring_size = s->context_model ? 3 : 2;
     int16_t *sample[3];
     s->run_index = 0;
 
@@ -297,7 +297,7 @@ static void encode_rgb_frame(FFV1Context *s, const uint8_t *src[3],
                              int w, int h, const int stride[3])
 {
     int x, y, p, i;
-    const int ring_size = s->avctx->context_model ? 3 : 2;
+    const int ring_size = s->context_model ? 3 : 2;
     int16_t *sample[MAX_PLANES][3];
     int lbd  = s->avctx->bits_per_raw_sample <= 8;
     int bits = s->avctx->bits_per_raw_sample > 0
@@ -418,7 +418,7 @@ static void write_header(FFV1Context *f)
                        0);
             for (j = 0; j < f->plane_count; j++) {
                 put_symbol(c, state, f->plane[j].quant_table_index, 0);
-                av_assert0(f->plane[j].quant_table_index == f->avctx->context_model);
+                av_assert0(f->plane[j].quant_table_index == f->context_model);
             }
         }
     }
@@ -671,12 +671,18 @@ FF_ENABLE_DEPRECATION_WARNINGS
             avctx, AV_LOG_WARNING,
             "Storing alpha plane, this will require a recent FFV1 decoder to playback!\n");
     }
+#if FF_API_PRIVATE_OPT
+FF_DISABLE_DEPRECATION_WARNINGS
+    if (avctx->context_model)
+        s->context_model = avctx->context_model;
     if (avctx->context_model > 1U) {
         av_log(avctx, AV_LOG_ERROR,
                "Invalid context model %d, valid values are 0 and 1\n",
                avctx->context_model);
         return AVERROR(EINVAL);
     }
+FF_ENABLE_DEPRECATION_WARNINGS
+#endif
 
     if (s->ac == AC_RANGE_CUSTOM_TAB)
         for (i = 1; i < 256; i++)
@@ -706,14 +712,14 @@ FF_ENABLE_DEPRECATION_WARNINGS
     }
     s->context_count[0] = (11 * 11 * 11        + 1) / 2;
     s->context_count[1] = (11 * 11 * 5 * 5 * 5 + 1) / 2;
-    memcpy(s->quant_table, s->quant_tables[avctx->context_model],
+    memcpy(s->quant_table, s->quant_tables[s->context_model],
            sizeof(s->quant_table));
 
     for (i = 0; i < s->plane_count; i++) {
         PlaneContext *const p = &s->plane[i];
 
         memcpy(p->quant_table, s->quant_table, sizeof(p->quant_table));
-        p->quant_table_index = avctx->context_model;
+        p->quant_table_index = s->context_model;
         p->context_count     = s->context_count[p->quant_table_index];
     }
 
@@ -860,7 +866,7 @@ static void encode_slice_header(FFV1Context *f, FFV1Context *fs)
                0);
     for (j = 0; j < f->plane_count; j++) {
         put_symbol(c, state, f->plane[j].quant_table_index, 0);
-        av_assert0(f->plane[j].quant_table_index == f->avctx->context_model);
+        av_assert0(f->plane[j].quant_table_index == f->context_model);
     }
     if (!f->frame->interlaced_frame)
         put_symbol(c, state, 3, 0);
@@ -1081,6 +1087,8 @@ static const AVOption options[] = {
             { .i64 = AC_RANGE_DEFAULT_TAB }, INT_MIN, INT_MAX, VE, "coder" },
         { "range_tab", "Range with custom table", 0, AV_OPT_TYPE_CONST,
             { .i64 = AC_RANGE_CUSTOM_TAB }, INT_MIN, INT_MAX, VE, "coder" },
+    { "context", "Context model", OFFSET(context_model), AV_OPT_TYPE_INT,
+            { .i64 = 0 }, 0, 1, VE },
 
     { NULL }
 };

libavcodec/huffyuvenc.c

@@ -26,6 +26,8 @@
  * huffyuv encoder
  */
 
+#include "libavutil/opt.h"
+
 #include "avcodec.h"
 #include "huffyuv.h"
 #include "huffman.h"
@@ -162,6 +164,12 @@ FF_DISABLE_DEPRECATION_WARNINGS
     avctx->coded_frame->pict_type = AV_PICTURE_TYPE_I;
     avctx->coded_frame->key_frame = 1;
 FF_ENABLE_DEPRECATION_WARNINGS
+#endif
+#if FF_API_PRIVATE_OPT
+FF_DISABLE_DEPRECATION_WARNINGS
+    if (avctx->context_model == 1)
+        s->context = avctx->context_model;
+FF_ENABLE_DEPRECATION_WARNINGS
 #endif
 
     switch (avctx->pix_fmt) {
@@ -187,15 +195,14 @@ FF_ENABLE_DEPRECATION_WARNINGS
     s->decorrelate = s->bitstream_bpp >= 24;
     s->predictor = avctx->prediction_method;
     s->interlaced = avctx->flags & AV_CODEC_FLAG_INTERLACED_ME ? 1 : 0;
-    if (avctx->context_model == 1) {
-        s->context = avctx->context_model;
+    if (s->context) {
         if (s->flags & (AV_CODEC_FLAG_PASS1 | AV_CODEC_FLAG_PASS2)) {
             av_log(avctx, AV_LOG_ERROR,
                    "context=1 is not compatible with "
                    "2 pass huffyuv encoding\n");
             return -1;
         }
-    }else s->context= 0;
+    }
 
     if (avctx->codec->id == AV_CODEC_ID_HUFFYUV) {
         if (avctx->pix_fmt == AV_PIX_FMT_YUV420P) {
@@ -204,12 +211,14 @@ FF_ENABLE_DEPRECATION_WARNINGS
                    "vcodec=ffvhuff or format=422p\n");
             return -1;
         }
-        if (avctx->context_model) {
+#if FF_API_PRIVATE_OPT
+        if (s->context) {
             av_log(avctx, AV_LOG_ERROR,
                    "Error: per-frame huffman tables are not supported "
                    "by huffyuv; use vcodec=ffvhuff\n");
             return -1;
         }
+#endif
         if (s->interlaced != ( s->height > 288 ))
             av_log(avctx, AV_LOG_INFO,
                    "using huffyuv 2.2.0 or newer interlacing flag\n");
@@ -686,6 +695,9 @@ static av_cold int encode_end(AVCodecContext *avctx)
     return 0;
 }
 
+#define OFFSET(x) offsetof(HYuvContext, x)
+#define VE AV_OPT_FLAG_VIDEO_PARAM | AV_OPT_FLAG_ENCODING_PARAM
+
 AVCodec ff_huffyuv_encoder = {
     .name           = "huffyuv",
     .long_name      = NULL_IF_CONFIG_SMALL("Huffyuv / HuffYUV"),
@@ -704,12 +716,25 @@ AVCodec ff_huffyuv_encoder = {
 };
 
 #if CONFIG_FFVHUFF_ENCODER
+static const AVOption ffhuffyuv_options[] = {
+    { "context", "Set per-frame huffman tables", OFFSET(context), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 1, VE },
+    { NULL }
+};
+
+static const AVClass ffhuffyuv_class = {
+    .class_name = "ffhuffyuv encoder",
+    .item_name  = av_default_item_name,
+    .option     = ffhuffyuv_options,
+    .version    = LIBAVUTIL_VERSION_INT,
+};
+
 AVCodec ff_ffvhuff_encoder = {
     .name           = "ffvhuff",
     .long_name      = NULL_IF_CONFIG_SMALL("Huffyuv FFmpeg variant"),
     .type           = AVMEDIA_TYPE_VIDEO,
     .id             = AV_CODEC_ID_FFVHUFF,
     .priv_data_size = sizeof(HYuvContext),
+    .priv_class     = &ffhuffyuv_class,
     .init           = encode_init,
     .encode2        = encode_frame,
     .close          = encode_end,

libavcodec/options_table.h

@@ -313,7 +313,9 @@ static const AVOption avcodec_options[] = {
 {"deflate", "deflate-based coder", 0, AV_OPT_TYPE_CONST, {.i64 = FF_CODER_TYPE_DEFLATE }, INT_MIN, INT_MAX, V|E, "coder"},
 #endif /* FF_API_UNUSED_MEMBERS */
 #endif /* FF_API_CODER_TYPE */
+#if FF_API_PRIVATE_OPT
 {"context", "context model", OFFSET(context_model), AV_OPT_TYPE_INT, {.i64 = DEFAULT }, INT_MIN, INT_MAX, V|E},
+#endif
 {"slice_flags", NULL, OFFSET(slice_flags), AV_OPT_TYPE_INT, {.i64 = DEFAULT }, INT_MIN, INT_MAX},
 #if FF_API_XVMC
 {"xvmc_acceleration", NULL, OFFSET(xvmc_acceleration), AV_OPT_TYPE_INT, {.i64 = DEFAULT }, INT_MIN, INT_MAX},