add support and config for z channel 4

configs/vae_magvit_v2/train/16x128x128_z=4.py

@@ -0,0 +1,82 @@
+num_frames = 16
+frame_interval = 3
+image_size = (128, 128)
+
+# Define dataset
+root = None
+data_path = "CSV_PATH"
+use_image_transform = False
+num_workers = 4
+video_contains_first_frame = False
+
+# Define acceleration
+dtype = "bf16"
+grad_checkpoint = True
+plugin = "zero2"
+sp_size = 1
+
+
+# Define model
+
+model = dict(
+    type="VAE_MAGVIT_V2",
+    in_out_channels = 3,
+    latent_embed_dim = 4,
+    filters = 128,
+    num_res_blocks = 4,
+    channel_multipliers = (1, 2, 2, 4),
+    temporal_downsample = (False, True, True),
+    num_groups = 32, # for nn.GroupNorm
+    kl_embed_dim = 4,
+    activation_fn = 'swish',
+    separate_first_frame_encoding = False,
+    disable_space = False,
+    custom_conv_padding = None
+)
+
+
+discriminator = dict(
+    type="DISCRIMINATOR_3D",
+    image_size = image_size,
+    num_frames = num_frames,
+    in_channels = 3,
+    filters = 128,
+    channel_multipliers = (2,4,4,4,4), # (2,4,4,4) for 64x64 resolution
+)
+
+
+# loss weights 
+logvar_init=0.0
+kl_loss_weight = 0.000001
+perceptual_loss_weight = 0.1 # use vgg is not None and more than 0
+discriminator_factor = 1.0 # for discriminator adversarial loss
+# discriminator_loss_weight = 0.5 # for generator adversarial loss
+generator_factor = 0.1 # SCH: generator adversarial loss, MAGVIT v2 uses 0.1
+lecam_loss_weight = None # NOTE: MAVGIT v2 use 0.001
+discriminator_loss_type="non-saturating"
+generator_loss_type="non-saturating"
+discriminator_start = 1000 # 50000 NOTE: change to correct val, debug use -1 for now
+gradient_penalty_loss_weight = None # 10 # SCH: MAGVIT uses 10, opensora plan doesn't use
+ema_decay = 0.999  # ema decay factor for generator
+
+
+# Others
+seed = 42
+outputs = "outputs"
+wandb = False
+
+# Training
+''' NOTE: 
+magvit uses about # samples (K) * epochs ~ 2-5 K,  num_frames = 4, reso = 128
+==> ours num_frams = 16, reso = 256, so samples (K) * epochs ~ [500 - 1200], 
+3-6 epochs for pexel, from pexel observation its correct
+'''
+
+epochs = 200
+log_every = 1
+ckpt_every = 200
+load = None
+
+batch_size = 4
+lr = 1e-4
+grad_clip = 1.0

opensora/models/vae/vae_3d_v2.py

@@ -739,6 +739,7 @@ class VAE_3D_V2(nn.Module): # , ModelMixin
         activation_fn = 'swish',
         in_out_channels = 4,
         kl_embed_dim = 64,
+        encoder_double_z = True,
         device="cpu",
         dtype="bf16",
     ):
@@ -782,7 +783,7 @@ class VAE_3D_V2(nn.Module): # , ModelMixin
             temporal_downsample=temporal_downsample,
             num_groups = num_groups, # for nn.GroupNorm
             # in_out_channels = in_out_channels,
-            latent_embed_dim = latent_embed_dim, 
+            latent_embed_dim = latent_embed_dim * 2 if encoder_double_z else latent_embed_dim, 
             # conv_downsample = conv_downsample, 
             disable_spatial_downsample=disable_space,
             custom_conv_padding = custom_conv_padding,
@@ -805,8 +806,11 @@ class VAE_3D_V2(nn.Module): # , ModelMixin
             device = device,
             dtype = dtype,
         )
-
-        self.quant_conv = nn.Conv3d(latent_embed_dim, 2*kl_embed_dim, 1, device=device, dtype=dtype)
+        
+        if encoder_double_z:
+            self.quant_conv = nn.Conv3d(2*latent_embed_dim, 2*kl_embed_dim, 1, device=device, dtype=dtype)
+        else:
+            self.quant_conv = nn.Conv3d(latent_embed_dim, 2*kl_embed_dim, 1, device=device, dtype=dtype)
         self.post_quant_conv = nn.Conv3d(kl_embed_dim, latent_embed_dim, 1, device=device, dtype=dtype)
 
     def get_latent_size(self, input_size):