[FFmpeg-devel] [PATCH v1] avcodec/libvpxenc: add a way to set VP9E_SET_SVC_REF_FRAME_CONFIG.

[Wonkap Jang]

In order to fine-control referencing schemes in VP9 encoding, there
is a need to use VP9E_SET_SVC_REF_FRAME_CONFIG method. This commit
provides a way to use the API through frame metadata.
---
 libavcodec/libvpxenc.c | 77 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 77 insertions(+)

diff --git a/libavcodec/libvpxenc.c b/libavcodec/libvpxenc.c
index a7c76eb835..dbe399bf72 100644
--- a/libavcodec/libvpxenc.c
+++ b/libavcodec/libvpxenc.c
@@ -125,6 +125,11 @@ typedef struct VPxEncoderContext {
      * encounter a frame with ROI side data.
      */
     int roi_warned;
+
+#if (VPX_ENCODER_ABI_VERSION >= 12) && CONFIG_LIBVPX_VP9_ENCODER
+    vpx_svc_ref_frame_config_t ref_frame_config;
+    AVDictionary *vpx_ref_frame_config;
+#endif
 } VPxContext;
 
 /** String mappings for enum vp8e_enc_control_id */
@@ -152,6 +157,7 @@ static const char *const ctlidstr[] = {
     [VP9E_SET_SVC_LAYER_ID]            = "VP9E_SET_SVC_LAYER_ID",
 #if VPX_ENCODER_ABI_VERSION >= 12
     [VP9E_SET_SVC_PARAMETERS]          = "VP9E_SET_SVC_PARAMETERS",
+    [VP9E_SET_SVC_REF_FRAME_CONFIG]    = "VP9E_SET_SVC_REF_FRAME_CONFIG",
 #endif
     [VP9E_SET_SVC]                     = "VP9E_SET_SVC",
 #if VPX_ENCODER_ABI_VERSION >= 11
@@ -394,6 +400,18 @@ static void vp8_ts_parse_int_array(int *dest, char *value, size_t value_len, int
     }
 }
 
+static void vp8_ts_parse_int64_array(int64_t *dest, char *value, size_t value_len, int max_entries)
+{
+    int dest_idx = 0;
+    char *saveptr = NULL;
+    char *token = av_strtok(value, ",", &saveptr);
+
+    while (token && dest_idx < max_entries) {
+        dest[dest_idx++] = strtoul(token, NULL, 10);
+        token = av_strtok(NULL, ",", &saveptr);
+    }
+}
+
 static void set_temporal_layer_pattern(int layering_mode, vpx_codec_enc_cfg_t *cfg,
                                        int *layer_flags, int *flag_periodicity)
 {
@@ -541,6 +559,48 @@ static int vpx_ts_param_parse(VPxContext *ctx, struct vpx_codec_enc_cfg *enccfg,
     return 0;
 }
 
+#if (VPX_ENCODER_ABI_VERSION >= 12) && CONFIG_LIBVPX_VP9_ENCODER
+static int vpx_ref_frame_config_parse(VPxContext *ctx, const struct vpx_codec_enc_cfg *enccfg,
+                              char *key, char *value, enum AVCodecID codec_id)
+{
+    size_t value_len = strlen(value);
+    int ss_number_layers = enccfg->ss_number_layers;
+    vpx_svc_ref_frame_config_t *ref_frame_config = &ctx->ref_frame_config;
+
+    if (!value_len)
+        return -1;
+
+    if (codec_id != AV_CODEC_ID_VP9)
+        return -1;
+
+    if (!strcmp(key, "rfc_update_buffer_slot")) {
+        vp8_ts_parse_int_array(ref_frame_config->update_buffer_slot, value, value_len, ss_number_layers);
+    } else if (!strcmp(key, "rfc_update_last")) {
+        vp8_ts_parse_int_array(ref_frame_config->update_last, value, value_len, ss_number_layers);
+    } else if (!strcmp(key, "rfc_update_golden")) {
+        vp8_ts_parse_int_array(ref_frame_config->update_golden, value, value_len, ss_number_layers);
+    } else if (!strcmp(key, "rfc_update_alt_ref")) {
+        vp8_ts_parse_int_array(ref_frame_config->update_alt_ref, value, value_len, ss_number_layers);
+    } else if (!strcmp(key, "rfc_lst_fb_idx")) {
+        vp8_ts_parse_int_array(ref_frame_config->lst_fb_idx, value, value_len, ss_number_layers);
+    } else if (!strcmp(key, "rfc_gld_fb_idx")) {
+        vp8_ts_parse_int_array(ref_frame_config->gld_fb_idx, value, value_len, ss_number_layers);
+    } else if (!strcmp(key, "rfc_alt_fb_idx")) {
+        vp8_ts_parse_int_array(ref_frame_config->alt_fb_idx, value, value_len, ss_number_layers);
+    } else if (!strcmp(key, "rfc_reference_last")) {
+        vp8_ts_parse_int_array(ref_frame_config->reference_last, value, value_len, ss_number_layers);
+    } else if (!strcmp(key, "rfc_reference_golden")) {
+        vp8_ts_parse_int_array(ref_frame_config->reference_golden, value, value_len, ss_number_layers);
+    } else if (!strcmp(key, "rfc_reference_alt_ref")) {
+        vp8_ts_parse_int_array(ref_frame_config->reference_alt_ref, value, value_len, ss_number_layers);
+    } else if (!strcmp(key, "rfc_reference_duration")) {
+        vp8_ts_parse_int64_array(ref_frame_config->duration, value, value_len, ss_number_layers);
+    }
+
+    return 0;
+}
+#endif
+
 #if CONFIG_LIBVPX_VP9_ENCODER
 static int set_pix_fmt(AVCodecContext *avctx, vpx_codec_caps_t codec_caps,
                        struct vpx_codec_enc_cfg *enccfg, vpx_codec_flags_t *flags,
@@ -1528,6 +1588,23 @@ static int vpx_encode(AVCodecContext *avctx, AVPacket *pkt,
 #endif
                 layer_id_valid = 1;
             }
+#if (VPX_ENCODER_ABI_VERSION >= 12) && CONFIG_LIBVPX_VP9_ENCODER
+            en = av_dict_get(frame->metadata, "ref-frame-config", NULL, 0);
+
+            if (en) {
+                AVDictionaryEntry* en2 = NULL;
+                av_dict_parse_string(&ctx->vpx_ref_frame_config, en->value, "=", ":", 0);
+
+                while ((en2 = av_dict_get(ctx->vpx_ref_frame_config, "", en2, AV_DICT_IGNORE_SUFFIX))) {
+                    if (vpx_ref_frame_config_parse(ctx, enccfg, en2->key, en2->value, avctx->codec_id) < 0)
+                        av_log(avctx, AV_LOG_WARNING,
+                               "Error parsing option '%s = %s'.\n",
+                               en2->key, en2->value);
+                }
+
+                codecctl_intp(avctx, VP9E_SET_SVC_REF_FRAME_CONFIG, (int *)&ctx->ref_frame_config);
+            }
+#endif
         }
 
         if (sd) {
-- 
2.29.2.299.gdc1121823c-goog