Don't show video load error if a blob has unrecognized or non-video m…

…edia type (#7528)

### What

Before:

![image](https://github.com/user-attachments/assets/acb4868a-b440-4a10-8019-8913246fa9a1)

After:

![image](https://github.com/user-attachments/assets/00385097-4420-4b47-bc15-759afac3876f)

... luckily I tried an obj file whose media type can't be recognized
from bytes (because obj is a wild text format), which made me run into
the corner case of video module not recognizing the format _and_ us not
recognizing the media type from the blob.

Counter example, trying to load a wmv:

![image](https://github.com/user-attachments/assets/846c20d9-ad46-42d6-94d9-ec6e175c2517)
(btw. I did so by renaming the file to mp4 and dragging it in, otherwise
we reject it earlier. Same could be achieved with direct log calls ofc)

### Checklist
* [x] I have read and agree to [Contributor
Guide](https://github.com/rerun-io/rerun/blob/main/CONTRIBUTING.md) and
the [Code of
Conduct](https://github.com/rerun-io/rerun/blob/main/CODE_OF_CONDUCT.md)
* [x] I've included a screenshot or gif (if applicable)
* [x] I have tested the web demo (if applicable):
* Using examples from latest `main` build:
[rerun.io/viewer](https://rerun.io/viewer/pr/7528?manifest_url=https://app.rerun.io/version/main/examples_manifest.json)
* Using full set of examples from `nightly` build:
[rerun.io/viewer](https://rerun.io/viewer/pr/7528?manifest_url=https://app.rerun.io/version/nightly/examples_manifest.json)
* [x] The PR title and labels are set such as to maximize their
usefulness for the next release's CHANGELOG
* [x] If applicable, add a new check to the [release
checklist](https://github.com/rerun-io/rerun/blob/main/tests/python/release_checklist)!
* [x] If have noted any breaking changes to the log API in
`CHANGELOG.md` and the migration guide

- [PR Build Summary](https://build.rerun.io/pr/7528)
- [Recent benchmark results](https://build.rerun.io/graphs/crates.html)
- [Wasm size tracking](https://build.rerun.io/graphs/sizes.html)

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full-check`.

crates/store/re_video/src/lib.rs

@@ -56,15 +56,24 @@ impl VideoData {
         } else if mp4::is_mp4(data) {
             "video/mp4".to_owned()
         } else {
-            // Technically this means that we failed to determine the media type altogether,
-            // but we don't want to call it `FailedToDetermineMediaType` since the rest of Rerun has
-            // access to `re_types::components::MediaType` which has a much wider range of media type detection.
-            return Err(VideoLoadError::UnsupportedVideoType);
+            return Err(VideoLoadError::UnrecognizedVideoFormat {
+                provided_media_type: media_type.map(|m| m.to_owned()),
+            });
         };
 
         match media_type.as_str() {
             "video/mp4" => mp4::load_mp4(data),
-            media_type => Err(VideoLoadError::UnsupportedMediaType(media_type.to_owned())),
+            media_type => {
+                if media_type.starts_with("video/") {
+                    Err(VideoLoadError::UnsupportedMediaType {
+                        provided_or_detected_media_type: media_type.to_owned(),
+                    })
+                } else {
+                    Err(VideoLoadError::MediaTypeIsNotAVideo {
+                        provided_or_detected_media_type: media_type.to_owned(),
+                    })
+                }
+            }
         }
     }
 
@@ -260,11 +269,19 @@ pub enum VideoLoadError {
     #[error("Video file has invalid sample entries")]
     InvalidSamples,
 
-    #[error("Video file has unsupported media type {0}")]
-    UnsupportedMediaType(String),
+    #[error("The media type of the blob is not a video: {provided_or_detected_media_type}")]
+    MediaTypeIsNotAVideo {
+        provided_or_detected_media_type: String,
+    },
 
+    #[error("Video file has unsupported media type {provided_or_detected_media_type}")]
+    UnsupportedMediaType {
+        provided_or_detected_media_type: String,
+    },
+
+    // Technically this is a "failed to detect" case, but the only formats we detect as of writing are the ones we support.
     #[error("Video file has unsupported format")]
-    UnsupportedVideoType,
+    UnrecognizedVideoFormat { provided_media_type: Option<String> },
 
     // `FourCC`'s debug impl doesn't quote the result
     #[error("Video track uses unsupported codec \"{0}\"")] // NOLINT

crates/viewer/re_data_ui/src/blob.rs

@@ -116,6 +116,7 @@ pub fn blob_preview_and_save_ui(
         let video_result = ctx.cache.entry(|c: &mut re_viewer_context::VideoCache| {
             c.entry(blob_row_id, blob, media_type.as_ref().map(|mt| mt.as_str()))
         });
+
         show_video_blob_info(
             ctx.render_ctx,
             ui,
@@ -170,6 +171,7 @@ fn show_video_blob_info(
     video_result: &Result<re_renderer::video::Video, VideoLoadError>,
     video_timestamp: Option<VideoTimestamp>,
 ) {
+    #[allow(clippy::match_same_arms)]
     match video_result {
         Ok(video) => {
             if ui_layout.is_single_line() {
@@ -264,6 +266,18 @@ fn show_video_blob_info(
                 }
             });
         }
+        Err(VideoLoadError::MediaTypeIsNotAVideo { .. }) => {
+            // Don't show an error if this wasn't a video in the first place.
+            // Unfortunately we can't easily detect here if the Blob was _supposed_ to be a video, for that we'd need tagged components!
+            // (User may have confidently logged a non-video format as Video, we should tell them that!)
+        }
+        Err(VideoLoadError::UnrecognizedVideoFormat {
+            provided_media_type: None,
+        }) => {
+            // If we couldn't detect the media type and the loader didn't know the format,
+            // we can't show an error for unrecognized formats since maybe this wasn't a video to begin with.
+            // See also `MediaTypeIsNotAVideo` case above.
+        }
         Err(err) => {
             if ui_layout.is_single_line() {
                 ui.error_label(&format!("Failed to load video: {err}"));

crates/viewer/re_data_ui/src/instance_path.rs

@@ -441,7 +441,8 @@ fn preview_if_blob_ui(
     let blob = blob.component_mono::<components::Blob>()?.ok()?;
     let media_type = component_map
         .get(&components::MediaType::name())
-        .and_then(|unit| unit.component_mono::<components::MediaType>()?.ok());
+        .and_then(|unit| unit.component_mono::<components::MediaType>()?.ok())
+        .or_else(|| components::MediaType::guess_from_data(&blob));
 
     let video_timestamp = component_map
         .get(&components::VideoTimestamp::name())