From e7bf79289e3ac2364cb543d16857dda42e1248c4 Mon Sep 17 00:00:00 2001
From: "byte[]" <byteslice@airmail.cc>
Date: Tue, 26 May 2020 21:35:11 -0400
Subject: [PATCH] forbid codec options which would not render in a browser

---
 src/validation.c | 69 +++++++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 66 insertions(+), 3 deletions(-)

diff --git a/src/validation.c b/src/validation.c
index ce6f382..b76d903 100644
--- a/src/validation.c
+++ b/src/validation.c
@@ -1,4 +1,5 @@
 #include <libavformat/avformat.h>
+#include <libavutil/pixdesc.h>
 #include <stdbool.h>
 #include <string.h>
 
@@ -7,6 +8,50 @@
 const AVRational t_1h = { 3600, 1 };
 const AVRational t_0h  = { 0, 1 };
 
+static int validate_video_pixel_format(enum AVPixelFormat format)
+{
+    switch (format) {
+    // Still image formats
+    case AV_PIX_FMT_RGB8:
+    case AV_PIX_FMT_RGB24:
+    case AV_PIX_FMT_RGB32:
+    case AV_PIX_FMT_RGB48:
+    case AV_PIX_FMT_RGBA:
+
+    // Video frame formats
+    case AV_PIX_FMT_YUV420P:
+    case AV_PIX_FMT_YUVJ420P:
+    case AV_PIX_FMT_YUV420P10LE:
+    case AV_PIX_FMT_YUV422P:
+    case AV_PIX_FMT_YUV422P10LE:
+    case AV_PIX_FMT_YUV444P:
+    case AV_PIX_FMT_YUV444P10LE:
+    case AV_PIX_FMT_YUV420P12LE:
+    case AV_PIX_FMT_YUV422P12LE:
+    case AV_PIX_FMT_YUV444P12LE:
+        return true;
+
+    default:
+        return false;
+    }
+}
+
+static int validate_audio_sample_format(enum AVSampleFormat format)
+{
+    switch (format) {
+    case AV_SAMPLE_FMT_FLT:
+    case AV_SAMPLE_FMT_FLTP:
+    case AV_SAMPLE_FMT_S16:
+    case AV_SAMPLE_FMT_S16P:
+    case AV_SAMPLE_FMT_S32:
+    case AV_SAMPLE_FMT_S32P:
+        return true;
+
+    default:
+        return false;
+    }
+}
+
 int mediatools_validate_video(AVFormatContext *format)
 {
     uint64_t num_vstreams = 0;
@@ -15,13 +60,31 @@ int mediatools_validate_video(AVFormatContext *format)
     int64_t astream_idx = -1;
 
     for (size_t i = 0; i < format->nb_streams; ++i) {
-        if (format->streams[i]->codecpar->codec_type == AVMEDIA_TYPE_VIDEO) {
+        AVCodecParameters *codecpar = format->streams[i]->codecpar;
+
+        if (codecpar->codec_type == AVMEDIA_TYPE_VIDEO) {
             num_vstreams++;
             vstream_idx = i;
-        }
-        if (format->streams[i]->codecpar->codec_type == AVMEDIA_TYPE_AUDIO) {
+
+            if (!validate_video_pixel_format(codecpar->format)) {
+                printf("Found unsupported pixel format %s\n", av_get_pix_fmt_name(codecpar->format));
+                return false;
+            }
+
+        } else if (codecpar->codec_type == AVMEDIA_TYPE_AUDIO) {
             num_astreams++;
             astream_idx = i;
+
+            if (!validate_audio_sample_format(codecpar->format)) {
+                printf("Found unsupported audio sample format %s\n", av_get_sample_fmt_name(codecpar->format));
+                return false;
+            }
+
+        } else if (codecpar->codec_type == AVMEDIA_TYPE_SUBTITLE) {
+            // Allow subtitles
+        } else {
+            printf("Unknown codec type %s\n", av_get_media_type_string(codecpar->codec_type));
+            return false;
         }
     }