Why was it that when the novel was placed in an MP4, the original text was replaced by letters?

I used to put novels in my MP4 to read, but today I put in another file, opened it and saw that it was all letters, there were no words at all, and then I looked at where the file was stored, it was very good, it was all words, and some of the files in my MP4 had words, and some were all Tian characters, just that the first paragraph was words, and at the end, it was all letters, not words.
What's going on ```````T_T

Answer 1

This question involved the format and storage method of the novel. For more details, please refer to the following explanation:

Fictions are usually written in a format known as "volume." Each volume contains multiple chapters, and each chapter is usually made up of multiple passages. When you store a novel in an MP4, you might choose to store each paragraph as a separate file instead of storing the entire chapter in the same file.

When a novel is stored in an MP4, the file system may automatically convert each paragraph into text format when reading the file and re-code the text into the desired format when needed, such as converting the paragraph into an browser for viewing.

During this process, some letters may be replaced with numbers or symbols to adapt to the MP4 file's coding standard. This may result in the original text of the novel being partially or completely replaced with letters to accommodate the needs of storage and transmission.

When the novel was stored in the MP4, the file system would automatically convert and code the text so that the text could be transmitted to a mobile device or playback device when needed.