Entendre dire que and entendre parler de are close in meaning, but they do not have the same sense.
Entendre dire que
Entendre dire que means receiving information, often indirectly (rumor, reported information).
- J’ai entendu dire que ce restaurant est bon. (I heard that this restaurant is good.)
- On entend dire que le prix du gaz va augmenter. (People say that the gas price will increase.)
- J’ai entendu dire qu’il part demain. (I heard that he is leaving tomorrow.)
Entendre parler de
Entendre parler de means knowing the existence of something, without precise information.
- J’ai entendu parler de ce film. (I have heard about this movie.)
- Tu as entendu parler de ce livre ? (Have you heard about this book?)
- Nous avons entendu parler de ce problème. (We have heard about this problem.)
Compare
- J’ai entendu dire que ce film est excellent. → information
- J’ai entendu parler de ce film. → I know it exists
- On entend dire que la situation est difficile. → rumor / info
- On entend parler de cette situation. → known topic
Attention
- Entendre dire que + clause (with que)
- Entendre parler de + noun
Advice
Remember this simple difference: dire que = information; parler de = general topic.