[FFmpeg-devel] [PATCH] avformat/hls: support decryption AES128 fmp4 m3u8 list

[Steven Liu]

m3u8 list create by:
mediafilesegmenter  --encrypt-key-file=keya.key --encrypt-key-url="keya.key" --iso-fragmented input.mp4

before this patch:
bogon:xxx StevenLiu$ ./ffplay -allowed_extensions ALL prog_index.m3u8
ffplay version N-91601-g551a029a18 Copyright (c) 2003-2018 the FFmpeg developers
  built with Apple LLVM version 9.1.0 (clang-902.0.39.2)
  configuration: --enable-libass --enable-opengl --enable-libx264 --enable-libmp3lame --enable-gpl --enable-nonfree --prefix=/usr/local --enable-libtesseract --enable-libspeex --enable-libfreetype --enable-libfontconfig --enable-libfdk-aac --enable-videotoolbox --enable-libxml2
  libavutil      56. 19.100 / 56. 19.100
  libavcodec     58. 22.101 / 58. 22.101
  libavformat    58. 17.101 / 58. 17.101
  libavdevice    58.  4.101 / 58.  4.101
  libavfilter     7. 26.100 /  7. 26.100
  libswscale      5.  2.100 /  5.  2.100
  libswresample   3.  2.100 /  3.  2.100
  libpostproc    55.  2.100 / 55.  2.100
[hls,applehttp @ 0x7fa30305f000] Opening 'fileSequence0.mp4' for reading
[hls,applehttp @ 0x7fa30305f000] Opening 'keya.key' for reading
[hls,applehttp @ 0x7fa30305f000] Opening 'crypto:fileSequence1.mp4' for reading
Format ac3 detected only with low score of 25, misdetection possible!
[ac3 @ 0x7fa304869000] frame sync errorvq=    0KB sq=    0B f=0/0
[ac3 @ 0x7fa304869000] new coupling strategy must be present in block 0
[ac3 @ 0x7fa304869000] error decoding the audio block
Input #0, hls,applehttp, from 'prog_index.m3u8':
  Duration: 00:00:59.87, start: 0.000000, bitrate: 0 kb/s
  Program 0
    Metadata:
      variant_bitrate : 0
    Stream #0:0: Audio: ac3, 48000 Hz, 5.1(side), fltp, 320 kb/s
    Metadata:
      variant_bitrate : 0
[ac3 @ 0x7fa30382b800] frame sync error
[ac3 @ 0x7fa30382b800] new coupling strategy must be present in block 0
[ac3 @ 0x7fa30382b800] error decoding the audio block
[ac3 @ 0x7fa30382b800] expacc 125 is out-of-range sq=    0B f=0/0
[ac3 @ 0x7fa30382b800] error decoding the audio block

after this patch:
bogon:xxx StevenLiu$ ./ffplay -allowed_extensions ALL prog_index.m3u8
ffplay version N-91602-g03fc3a68e7 Copyright (c) 2003-2018 the FFmpeg developers
  built with Apple LLVM version 9.1.0 (clang-902.0.39.2)
  configuration: --enable-libass --enable-opengl --enable-libx264 --enable-libmp3lame --enable-gpl --enable-nonfree --prefix=/usr/local --enable-libtesseract --enable-libspeex --enable-libfreetype --enable-libfontconfig --enable-libfdk-aac --enable-videotoolbox --enable-libxml2
  libavutil      56. 19.100 / 56. 19.100
  libavcodec     58. 22.101 / 58. 22.101
  libavformat    58. 17.101 / 58. 17.101
  libavdevice    58.  4.101 / 58.  4.101
  libavfilter     7. 26.100 /  7. 26.100
  libswscale      5.  2.100 /  5.  2.100
  libswresample   3.  2.100 /  3.  2.100
  libpostproc    55.  2.100 / 55.  2.100
[hls,applehttp @ 0x7f86e1868000] Opening 'keya.key' for reading/0
[hls,applehttp @ 0x7f86e1868000] Opening 'crypto:fileSequence0.mp4' for reading
[hls,applehttp @ 0x7f86e1868000] Opening 'crypto:fileSequence1.mp4' for reading
Input #0, hls,applehttp, from 'prog_index.m3u8':
  Duration: 00:00:59.87, start: 10.000000, bitrate: 0 kb/s
  Program 0
    Metadata:
      variant_bitrate : 0
    Stream #0:0: Video: h264 (High) (avc1 / 0x31637661), yuv420p, 1920x1080 [SAR 1:1 DAR 16:9], 992 kb/s, 30 fps, 30 tbr, 30k tbn, 60 tbc
    Metadata:
      variant_bitrate : 0
      major_brand     : mp42
      minor_version   : 1
      compatible_brands: mp41mp42isomhlsf
      creation_time   : 2018-08-13T10:04:15.000000Z
    Stream #0:1: Audio: ac3 (ac-3 / 0x332D6361), 48000 Hz, 5.1(side), fltp, 232 kb/s
    Metadata:
      variant_bitrate : 0
[hls,applehttp @ 0x7f86e1868000] Opening 'crypto:fileSequence2.mp4' for reading

Signed-off-by: Steven Liu <lq at chinaffmpeg.org>
---
 libavformat/hls.c | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/libavformat/hls.c b/libavformat/hls.c
index 3d4f7f2647..8ad08baaed 100644
--- a/libavformat/hls.c
+++ b/libavformat/hls.c
@@ -811,6 +811,27 @@ static int parse_playlist(HLSContext *c, const char *url,
             ff_parse_key_value(ptr, (ff_parse_key_val_cb) handle_init_section_args,
                                &info);
             cur_init_section = new_init_section(pls, &info, url);
+            cur_init_section->key_type = key_type;
+            if (has_iv) {
+                memcpy(cur_init_section->iv, iv, sizeof(iv));
+            } else {
+                int seq = pls->start_seq_no + pls->n_segments;
+                memset(cur_init_section->iv, 0, sizeof(cur_init_section->iv));
+                AV_WB32(cur_init_section->iv + 12, seq);
+            }
+
+            if (key_type != KEY_NONE) {
+                ff_make_absolute_url(tmp_str, sizeof(tmp_str), url, key);
+                cur_init_section->key = av_strdup(tmp_str);
+                if (!cur_init_section->key) {
+                    av_free(cur_init_section);
+                    ret = AVERROR(ENOMEM);
+                    goto fail;
+                }
+            } else {
+                cur_init_section->key = NULL;
+            }
+
         } else if (av_strstart(line, "#EXT-X-ENDLIST", &ptr)) {
             if (pls)
                 pls->finished = 1;
-- 
2.15.2 (Apple Git-101.1)