Fix min-snr-gamma for v-prediction and ZSNR.

This fixes min-snr for vpred+zsnr by dividing directly by SNR+1.
The old implementation did it in two steps: (min-snr/snr) * (snr/(snr+1)), which causes division by zero when combined with --zero_terminal_snr
This commit is contained in:
feffy380
2023-11-07 23:02:25 +01:00
parent f3e69531c3
commit 6b3148fd3f
9 changed files with 14 additions and 11 deletions

View File

@@ -355,7 +355,7 @@ def train(args):
loss = loss.mean([1, 2, 3])
if args.min_snr_gamma:
loss = apply_snr_weight(loss, timesteps, noise_scheduler, args.min_snr_gamma)
loss = apply_snr_weight(loss, timesteps, noise_scheduler, args.min_snr_gamma, args.v_parameterization)
if args.scale_v_pred_loss_like_noise_pred:
loss = scale_v_prediction_loss_like_noise_prediction(loss, timesteps, noise_scheduler)
if args.debiased_estimation_loss:

View File

@@ -57,10 +57,13 @@ def fix_noise_scheduler_betas_for_zero_terminal_snr(noise_scheduler):
noise_scheduler.alphas_cumprod = alphas_cumprod
def apply_snr_weight(loss, timesteps, noise_scheduler, gamma):
def apply_snr_weight(loss, timesteps, noise_scheduler, gamma, v_prediction=False):
snr = torch.stack([noise_scheduler.all_snr[t] for t in timesteps])
gamma_over_snr = torch.div(torch.ones_like(snr) * gamma, snr)
snr_weight = torch.minimum(gamma_over_snr, torch.ones_like(gamma_over_snr)).float().to(loss.device) # from paper
min_snr_gamma = torch.minimum(snr, torch.full_like(snr, gamma))
if v_prediction:
snr_weight = torch.div(min_snr_gamma, snr+1).float().to(loss.device)
else:
snr_weight = torch.div(min_snr_gamma, snr).float().to(loss.device)
loss = loss * snr_weight
return loss

View File

@@ -460,7 +460,7 @@ def train(args):
loss = loss * loss_weights
if args.min_snr_gamma:
loss = apply_snr_weight(loss, timesteps, noise_scheduler, args.min_snr_gamma)
loss = apply_snr_weight(loss, timesteps, noise_scheduler, args.min_snr_gamma, args.v_parameterization)
if args.scale_v_pred_loss_like_noise_pred:
loss = scale_v_prediction_loss_like_noise_prediction(loss, timesteps, noise_scheduler)
if args.v_pred_like_loss:

View File

@@ -430,7 +430,7 @@ def train(args):
loss = loss * loss_weights
if args.min_snr_gamma:
loss = apply_snr_weight(loss, timesteps, noise_scheduler, args.min_snr_gamma)
loss = apply_snr_weight(loss, timesteps, noise_scheduler, args.min_snr_gamma, args.v_parameterization)
if args.scale_v_pred_loss_like_noise_pred:
loss = scale_v_prediction_loss_like_noise_prediction(loss, timesteps, noise_scheduler)
if args.v_pred_like_loss:

View File

@@ -449,7 +449,7 @@ def train(args):
loss = loss * loss_weights
if args.min_snr_gamma:
loss = apply_snr_weight(loss, timesteps, noise_scheduler, args.min_snr_gamma)
loss = apply_snr_weight(loss, timesteps, noise_scheduler, args.min_snr_gamma, args.v_parameterization)
loss = loss.mean() # 平均なのでbatch_sizeで割る必要なし

View File

@@ -342,7 +342,7 @@ def train(args):
loss = loss * loss_weights
if args.min_snr_gamma:
loss = apply_snr_weight(loss, timesteps, noise_scheduler, args.min_snr_gamma)
loss = apply_snr_weight(loss, timesteps, noise_scheduler, args.min_snr_gamma, args.v_parameterization)
if args.scale_v_pred_loss_like_noise_pred:
loss = scale_v_prediction_loss_like_noise_prediction(loss, timesteps, noise_scheduler)
if args.debiased_estimation_loss:

View File

@@ -812,7 +812,7 @@ class NetworkTrainer:
loss = loss * loss_weights
if args.min_snr_gamma:
loss = apply_snr_weight(loss, timesteps, noise_scheduler, args.min_snr_gamma)
loss = apply_snr_weight(loss, timesteps, noise_scheduler, args.min_snr_gamma, args.v_parameterization)
if args.scale_v_pred_loss_like_noise_pred:
loss = scale_v_prediction_loss_like_noise_prediction(loss, timesteps, noise_scheduler)
if args.v_pred_like_loss:

View File

@@ -578,7 +578,7 @@ class TextualInversionTrainer:
loss = loss * loss_weights
if args.min_snr_gamma:
loss = apply_snr_weight(loss, timesteps, noise_scheduler, args.min_snr_gamma)
loss = apply_snr_weight(loss, timesteps, noise_scheduler, args.min_snr_gamma, args.v_parameterization)
if args.scale_v_pred_loss_like_noise_pred:
loss = scale_v_prediction_loss_like_noise_prediction(loss, timesteps, noise_scheduler)
if args.v_pred_like_loss:

View File

@@ -469,7 +469,7 @@ def train(args):
loss = loss * loss_weights
if args.min_snr_gamma:
loss = apply_snr_weight(loss, timesteps, noise_scheduler, args.min_snr_gamma)
loss = apply_snr_weight(loss, timesteps, noise_scheduler, args.min_snr_gamma, args.v_parameterization)
if args.scale_v_pred_loss_like_noise_pred:
loss = scale_v_prediction_loss_like_noise_prediction(loss, timesteps, noise_scheduler)
if args.debiased_estimation_loss: