[FFmpeg-devel] [PATCH] libavformat/smush: read ANIMv2 a/v parameters

[Manuel Lauss]

SMUSH ANIM files with subversion 2 provide additional fields for
framerate and samplerate, use them if available, otherwise
default to 12 fps which is the default for almost all ANIMv2
since 1995.

Fixes the too-fast playback of test files from LucasArts games
released 1995-1997.  It was not noticed since Audio for
those isn't decoded by ffmpeg.

Signed-off-by: Manuel Lauss <manuel.lauss at gmail.com>
---
 libavformat/smush.c | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/libavformat/smush.c b/libavformat/smush.c
index 0877f7faff..25730e5816 100644
--- a/libavformat/smush.c
+++ b/libavformat/smush.c
@@ -51,7 +51,7 @@ static int smush_read_header(AVFormatContext *ctx)
     AVStream *vst, *ast;
     uint32_t magic, nframes, size, subversion, i;
     uint32_t width = 0, height = 0, got_audio = 0, read = 0;
-    uint32_t sample_rate, channels, palette[256];
+    uint32_t sample_rate, channels, palette[256], frame_rate = 15;
     int ret;
 
     magic = avio_rb32(pb);
@@ -76,7 +76,16 @@ static int smush_read_header(AVFormatContext *ctx)
         for (i = 0; i < 256; i++)
             palette[i] = avio_rb24(pb);
 
-        avio_skip(pb, size - (3 * 256 + 6));
+        if (subversion > 1) {
+            frame_rate = avio_rl32(pb);
+            avio_skip(pb, 4);            // max size of FRME chunk in file
+            sample_rate = avio_rl32(pb);
+            avio_skip(pb, size - (3 * 256 + 6 + 3 * 4));
+            if (frame_rate < 1 || frame_rate > 70)
+                frame_rate = 12;
+        } else {
+            avio_skip(pb, size - (3 * 256 + 6));
+        }
     } else if (magic == MKBETAG('S', 'A', 'N', 'M')) {
         if (avio_rb32(pb) != MKBETAG('S', 'H', 'D', 'R'))
             return AVERROR_INVALIDDATA;
@@ -146,7 +155,7 @@ static int smush_read_header(AVFormatContext *ctx)
 
     smush->video_stream_index = vst->index;
 
-    avpriv_set_pts_info(vst, 64, 1, 15);
+    avpriv_set_pts_info(vst, 64, 1, frame_rate);
 
     vst->start_time        = 0;
     vst->duration          =
-- 
2.47.0