fix(raw): Fix premature EOF and timing overflow in raw_loop (CCExtractor#1565)

Fix raw caption file processing that would stop at exactly 9:43:00 (2MB).

Root causes and fixes:
1. Premature EOF: After processing first chunk (BUFSIZE ~2MB), data->len
   was never reset. On next iteration, general_get_more_data() calculated
   want = BUFSIZE - len = 0 and returned EOF immediately.
   Fix: Reset data->len = 0 after each chunk and change loop condition.

2. 32-bit integer overflow: The calculation cb_field1 * 1001 / 30 * 90
   overflowed for large cb_field1 values (>1M). For example,
   34,989,487 * 90 = 3,149,053,830 exceeds 32-bit signed max.
   Fix: Cast cb_field1 to LLONG before multiplication.

3. Timing initialization: Raw mode needs min_pts=0, sync_pts=0, and
   pts_set=MinPtsSet for correct fts_now calculation.

Tested with sample files from issue CCExtractor#1565:
- DTV3.raw: Now processes to 17:59:56 (was stopping at 9:43)
- DTV4.raw: Now processes to 14:00:00 (was stopping at 9:43)
- DTV5.raw: Now processes to 13:19:59 (was stopping at 9:43)

Closes CCExtractor#1565

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: cfsmp3

src/lib_ccx/general_loop.c

@@ -534,8 +534,14 @@ int raw_loop(struct lib_ccx_ctx *ctx)
 	dec_ctx = update_decoder_list(ctx);
 	dec_sub = &dec_ctx->dec_sub;
 
-	set_current_pts(dec_ctx->timing, 90);
-	set_fts(dec_ctx->timing); // Now set the FTS related variables
+	// For raw mode, timing is derived from the caption block counter (cb_field1).
+	// We set min_pts=0 and pts_set=MinPtsSet so set_fts() will calculate fts_now.
+	// Initialize timing for raw mode - no video PTS, just caption block counting.
+	dec_ctx->timing->min_pts = 0;
+	dec_ctx->timing->sync_pts = 0;
+	dec_ctx->timing->pts_set = 2; // MinPtsSet
+	set_current_pts(dec_ctx->timing, 0);
+	set_fts(dec_ctx->timing);
 
 	do
 	{
@@ -561,8 +567,13 @@ int raw_loop(struct lib_ccx_ctx *ctx)
 		else
 		{
 			ret = process_raw(dec_ctx, dec_sub, data->buffer, data->len);
-			// For regular raw format, advance timing based on field 1 blocks
-			add_current_pts(dec_ctx->timing, cb_field1 * 1001 / 30 * (MPEG_CLOCK_FREQ / 1000));
+			// For raw mode, cb_field1 is incremented by do_cb() for each CC pair.
+			// After processing each chunk, add the accumulated time to current_pts
+			// and call set_fts() to update fts_now. set_fts() resets cb_field1 to 0,
+			// so each chunk's timing is added incrementally.
+			// Note: Cast cb_field1 to LLONG to prevent 32-bit integer overflow
+			// when calculating ticks for large raw files (issue #1565).
+			add_current_pts(dec_ctx->timing, (LLONG)cb_field1 * 1001 / 30 * (MPEG_CLOCK_FREQ / 1000));
 			set_fts(dec_ctx->timing);
 		}
 
@@ -573,7 +584,12 @@ int raw_loop(struct lib_ccx_ctx *ctx)
 			dec_sub->got_output = 0;
 		}
 
-	} while (data->len);
+		// Reset buffer length after processing so we can read more data
+		// Without this, data->len stays at BUFSIZE and general_get_more_data
+		// returns CCX_EOF prematurely (it calculates want = BUFSIZE - len = 0)
+		data->len = 0;
+
+	} while (1); // Loop exits via break on CCX_EOF or terminate_asap
 	free(data);
 	return caps;
 }