avformat/mov: Increase support for common encryption.

- Parse schm atom to get different encryption schemes.
- Allow senc atom to appear in track fragments.
- Allow 16-byte IVs.
- Allow constant IVs (specified in tenc).
- Allow only tenc to specify encryption (i.e. no senc/saiz/saio).
- Use sample descriptor to detect clear fragments.

This doesn't support:
- Different sample descriptor holding different encryption info.
  - Only first sample descriptor can be encrypted.
- Encrypted sample groups (i.e. seig).
- Non-'cenc' encryption scheme when using -decryption_key.

Signed-off-by: Jacob Trimble <modmaker@google.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

1 files changed, 14 insertions, 0 deletions

diff --git a/libavformat/isom.h b/libavformat/isom.h
index 4da34142f0..eb942cf882 100644
--- a/libavformat/isom.h
+++ b/libavformat/isom.h
@@ -27,6 +27,7 @@
 #include <stddef.h>
 #include <stdint.h>
 
+#include "libavutil/encryption_info.h"
 #include "libavutil/mastering_display_metadata.h"
 #include "libavutil/spherical.h"
 #include "libavutil/stereo3d.h"
@@ -108,12 +109,20 @@ typedef struct MOVSbgp {
     unsigned int index;
 } MOVSbgp;
 
+typedef struct MOVEncryptionIndex {
+    // Individual encrypted samples.  If there are no elements, then the default
+    // settings will be used.
+    unsigned int nb_encrypted_samples;
+    AVEncryptionInfo **encrypted_samples;
+} MOVEncryptionIndex;
+
 typedef struct MOVFragmentStreamInfo {
     int id;
     int64_t sidx_pts;
     int64_t first_tfra_pts;
     int64_t tfdt_dts;
     int index_entry;
+    MOVEncryptionIndex *encryption_index;
 } MOVFragmentStreamInfo;
 
 typedef struct MOVFragmentIndexItem {
@@ -215,6 +224,7 @@ typedef struct MOVStreamContext {
 
     int has_sidx;  // If there is an sidx entry for this stream.
     struct {
+        // TODO: Remove once old methods are removed from mov.c
         int use_subsamples;
         uint8_t* auxiliary_info;
         uint8_t* auxiliary_info_end;
@@ -223,7 +233,11 @@ typedef struct MOVStreamContext {
         uint8_t* auxiliary_info_sizes;
         size_t auxiliary_info_sizes_count;
         int64_t auxiliary_info_index;
+
         struct AVAESCTR* aes_ctr;
+        unsigned int per_sample_iv_size;  // Either 0, 8, or 16.
+        AVEncryptionInfo *default_encrypted_sample;
+        MOVEncryptionIndex *encryption_index;
     } cenc;
 } MOVStreamContext;