[FFmpeg-devel] [PATCH v2 1/3] libaomenc: Add support for tiles

[Mark Thompson]

Adds an option to specify the number of tile rows and columns, then uses
equal-sized tiles to fill the frame.
---
 libavcodec/libaomenc.c | 54 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 54 insertions(+)

diff --git a/libavcodec/libaomenc.c b/libavcodec/libaomenc.c
index 6a79d9b873..3ccff0e0fb 100644
--- a/libavcodec/libaomenc.c
+++ b/libavcodec/libaomenc.c
@@ -68,6 +68,7 @@ typedef struct AOMEncoderContext {
     int static_thresh;
     int drop_threshold;
     int noise_sensitivity;
+    int tile_cols, tile_rows;
 } AOMContext;
 
 static const char *const ctlidstr[] = {
@@ -79,6 +80,7 @@ static const char *const ctlidstr[] = {
     [AV1E_SET_COLOR_PRIMARIES]  = "AV1E_SET_COLOR_PRIMARIES",
     [AV1E_SET_MATRIX_COEFFICIENTS] = "AV1E_SET_MATRIX_COEFFICIENTS",
     [AV1E_SET_TRANSFER_CHARACTERISTICS] = "AV1E_SET_TRANSFER_CHARACTERISTICS",
+    [AV1E_SET_SUPERBLOCK_SIZE]  = "AV1E_SET_SUPERBLOCK_SIZE",
 };
 
 static av_cold void log_encoder_error(AVCodecContext *avctx, const char *desc)
@@ -143,6 +145,10 @@ static av_cold void dump_enc_cfg(AVCodecContext *avctx,
            width, "kf_mode:",     cfg->kf_mode,
            width, "kf_min_dist:", cfg->kf_min_dist,
            width, "kf_max_dist:", cfg->kf_max_dist);
+    av_log(avctx, level, "tile settings\n"
+                         "  %*s%d\n  %*s%d\n",
+           width, "tile_width_count:",  cfg->tile_width_count,
+           width, "tile_height_count:", cfg->tile_height_count);
     av_log(avctx, level, "\n");
 }
 
@@ -294,6 +300,7 @@ static av_cold int aom_init(AVCodecContext *avctx,
     int res;
     aom_img_fmt_t img_fmt;
     aom_codec_caps_t codec_caps = aom_codec_get_caps(iface);
+    aom_superblock_size_t superblock_size = AOM_SUPERBLOCK_SIZE_DYNAMIC;
 
     av_log(avctx, AV_LOG_INFO, "%s\n", aom_codec_version_str());
     av_log(avctx, AV_LOG_VERBOSE, "%s\n", aom_codec_build_config());
@@ -431,6 +438,50 @@ static av_cold int aom_init(AVCodecContext *avctx,
 
     enccfg.g_error_resilient = ctx->error_resilient;
 
+    if (ctx->tile_cols && ctx->tile_rows) {
+        int sb_size, sb_width, sb_height;
+        int cols_per_tile, cols_step, rows_per_tile, rows_step, i;
+
+        // Default to 128x128 superblocks if they fit, otherwise use 64x64.
+        if ((avctx->width  + 127) / 128 < ctx->tile_cols ||
+            (avctx->height + 127) / 128 < ctx->tile_rows) {
+            sb_size = 64;
+            superblock_size = AOM_SUPERBLOCK_SIZE_64X64;
+        } else {
+            sb_size = 128;
+            superblock_size = AOM_SUPERBLOCK_SIZE_128X128;
+        }
+
+        if ((avctx->width  + sb_size - 1) / sb_size < ctx->tile_cols ||
+            (avctx->height + sb_size - 1) / sb_size < ctx->tile_rows) {
+            av_log(avctx, AV_LOG_ERROR, "Invalid tile sizing: frame not "
+                   "large enough to fit specified tile arrangement.\n");
+            return AVERROR(EINVAL);
+        }
+        if (ctx->tile_cols > MAX_TILE_WIDTHS ||
+            ctx->tile_rows > MAX_TILE_HEIGHTS) {
+            av_log(avctx, AV_LOG_ERROR, "Invalid tile sizing: at most %dx%d "
+                   "tiles allowed.\n", MAX_TILE_WIDTHS, MAX_TILE_HEIGHTS);
+            return AVERROR(EINVAL);
+        }
+
+        enccfg.tile_width_count  = ctx->tile_cols;
+        enccfg.tile_height_count = ctx->tile_rows;
+
+        sb_width  = (avctx->width  + sb_size - 1) / sb_size;
+        sb_height = (avctx->height + sb_size - 1) / sb_size;
+
+        cols_per_tile = sb_width / ctx->tile_cols;
+        cols_step     = sb_width % ctx->tile_cols;
+        for (i = 0; i < ctx->tile_cols; i++)
+            enccfg.tile_widths[i] = cols_per_tile + (i < cols_step);
+
+        rows_per_tile = sb_height / ctx->tile_rows;
+        rows_step     = sb_height % ctx->tile_rows;
+        for (i = 0; i < ctx->tile_rows; i++)
+            enccfg.tile_heights[i] = rows_per_tile + (i < rows_step);
+    }
+
     dump_enc_cfg(avctx, &enccfg);
     /* Construct Encoder Context */
     res = aom_codec_enc_init(&ctx->encoder, iface, &enccfg, flags);
@@ -454,6 +505,8 @@ static av_cold int aom_init(AVCodecContext *avctx,
     codecctl_int(avctx, AV1E_SET_TRANSFER_CHARACTERISTICS, avctx->color_trc);
     set_color_range(avctx);
 
+    codecctl_int(avctx, AV1E_SET_SUPERBLOCK_SIZE, superblock_size);
+
     // provide dummy value to initialize wrapper, values will be updated each _encode()
     aom_img_wrap(&ctx->rawimg, img_fmt, avctx->width, avctx->height, 1,
                  (unsigned char*)1);
@@ -742,6 +795,7 @@ static const AVOption options[] = {
     { "static-thresh",    "A change threshold on blocks below which they will be skipped by the encoder", OFFSET(static_thresh), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, INT_MAX, VE },
     { "drop-threshold",   "Frame drop threshold", offsetof(AOMContext, drop_threshold), AV_OPT_TYPE_INT, {.i64 = 0 }, INT_MIN, INT_MAX, VE },
     { "noise-sensitivity", "Noise sensitivity", OFFSET(noise_sensitivity), AV_OPT_TYPE_INT, {.i64 = 0 }, 0, 4, VE},
+    { "tiles",            "Tile rows x columns", OFFSET(tile_cols), AV_OPT_TYPE_IMAGE_SIZE, { .str = NULL }, 0, 0, VE },
     { NULL }
 };
 
-- 
2.18.0