codec/ecu: Introduce new generic Error Concealment Unit abstraction

We don't want to expose the details of a given ECU implementation to
the user (e.g. osmo-bts), but have a generic abstraction layer where
an ECU implementation can simply register a few call-back functions
with the generic core.

As the developer and copyright holder of the related code, I hereby
state that any ECU implementation using 'struct osmo_ecu_ops' and
registering with the 'osmo_ecu_register()' function shall not be
considered as a derivative work under any applicable copyright law;
the copyleft terms of GPLv2 shall hence not apply to any such ECU
implementation.

The intent of the above exception is to allow anyone to combine
third party Error Concealment Unit implementations with libosmocore,
including but not limited to such published by ETSI.

Change-Id: I4d33c9c7c2d4c7462ff38a49c178b65accae1915
diff --git a/tests/codec/codec_ecu_fr_test.ok b/tests/codec/codec_ecu_fr_test.ok
index 3cc35af..30163a9 100644
--- a/tests/codec/codec_ecu_fr_test.ok
+++ b/tests/codec/codec_ecu_fr_test.ok
@@ -1,3 +1,4 @@
+=> Testing FR concealment (simple, consecutive bad frames)
 Start with: d9ec9be212901f802335598c501f805bad3d4ba01f809b69df5a501f809cd1b4da, XMAXC: [3f, 3f, 3f, 3f]
 conceal: 00, result: d9ec9be212901f802335598c501f805bad3d4ba01f809b69df5a501f809cd1b4da XMAXC: [3f, 3f, 3f, 3f]
 conceal: 01, result: d9ec9be212901d802335598c501d805bad3d4ba01d809b69df5a501d809cd1b4da XMAXC: [3b, 3b, 3b, 3b]
@@ -40,6 +41,181 @@
 conceal: 17, result: d00000000000000000000000000000000000000000000000000000000000000000 XMAXC: [0, 0, 0, 0]
 conceal: 18, result: d00000000000000000000000000000000000000000000000000000000000000000 XMAXC: [0, 0, 0, 0]
 conceal: 19, result: d00000000000000000000000000000000000000000000000000000000000000000 XMAXC: [0, 0, 0, 0]
+
+=> Testing FR concealment (realistic, various bad frames)
+Frame No. 000:
+ * input:  d9aa93ae63de00471a91b95b8660471392b4a2daa037628f391c624039258dc723
+ * output: d9aa93ae63de00471a91b95b8660471392b4a2daa037628f391c624039258dc723
+Frame No. 001:
+ * input:  d8eb83699a66c036ec89b7246e6034dc8d48948620589b7256e3a6603b2371b8da
+ * output: d8eb83699a66c036ec89b7246e6034dc8d48948620589b7256e3a6603b2371b8da
+Frame No. 002:
+ * input:  d967abaa1cbe4035238da6ace4c036d46ec69ba600391c4eb8a2b040591c6a3924
+ * output: d967abaa1cbe4035238da6ace4c036d46ec69ba600391c4eb8a2b040591c6a3924
+Frame No. 003:
+ * input:  d8e8a42662c240472469b91bd2e0452291b6dba600495b8e38dcb020491a71c91b
+ * output: d8e8a42662c240472469b91bd2e0452291b6dba600495b8e38dcb020491a71c91b
+Frame No. 004:
+ * input:  da2aac1ddbb00036e46e26dcec6039138db923822047137248e3560048e38dc8e3
+ * output: da2aac1ddbb00036e46e26dcec6039138db923822047137248e3560048e38dc8e3
+Frame No. 005:
+ * input:  d929ab2a9b5240395b6dc72ba020469c8d551c5440349c9148e36a4036a372471b
+ * output: d929ab2a9b5240395b6dc72ba020469c8d551c5440349c9148e36a4036a372471b
+Frame No. 006:
+ * input:  d9eb93215bb8a0271c69c724682036db71c71a94a0372491b72bee4044eb71b923
+ * output: d9eb93215bb8a0271c69c724682036db71c71a94a0372491b72bee4044eb71b923
+Frame No. 007:
+ * input:  d9ab9aa19abc40391b6e5ae2ee40471b91c6dbe820492291b8e4b84036e47238db
+ * output: d9ab9aa19abc40391b6e5ae2ee40471b91c6dbe820492291b8e4b84036e47238db
+Frame No. 008:
+ * input:  d96b9be9db782044e371b55cb200389491c69b8ea034e271c8d3808038ec6db8e3
+ * output: d96b9be9db782044e371b55cb200389491c69b8ea034e271c8d3808038ec6db8e3
+Frame No. 009:
+ * input:  d9aa9365e3f060375c6db6ebc4c02764b1c51b78a0571c91a723de6049248dc8dd
+ * output: d9aa9365e3f060375c6db6ebc4c02764b1c51b78a0571c91a723de6049248dc8dd
+Frame No. 010:
+ * input:  (bad)
+ * output: d9aa9365e3f060375c6db6ebc4c02764b1c51b78a0571c91a723de6049248dc8dd
+Frame No. 011:
+ * input:  d9ea9c219ce60046e38d3724e0c034e56e36eb7e0038d471b8dcb260491b8dbb23
+ * output: d9ea9c219ce60046e38d3724e0c034e56e36eb7e0038d471b8dcb260491b8dbb23
+Frame No. 012:
+ * input:  d9e89be9d9e0a0391b6dd6a4624029247138e3a2a04713922524de0036db69d91c
+ * output: d9e89be9d9e0a0391b6dd6a4624029247138e3a2a04713922524de0036db69d91c
+Frame No. 013:
+ * input:  d9699422a2b6a048dd90c91c6a802b6259395c8880575b4a58e4ac20269d7248d4
+ * output: d9699422a2b6a048dd90c91c6a802b6259395c8880575b4a58e4ac20269d7248d4
+Frame No. 014:
+ * input:  d967ac5b1baae0371c71b8ab9c804a9e8e58a55a8038626ec8dcb640395c7244dc
+ * output: d967ac5b1baae0371c71b8ab9c804a9e8e58a55a8038626ec8dcb640395c7244dc
+Frame No. 015:
+ * input:  d9e8a3e262e68027638db52b88a038634e471a7ec049136e3b1bc8402923adcad2
+ * output: d9e8a3e262e68027638db52b88a038634e471a7ec049136e3b1bc8402923adcad2
+Frame No. 016:
+ * input:  d8eab36e1bbe0046e34d491b608035137658d3524044e48e375cdac0472b9238d4
+ * output: d8eab36e1bbe0046e34d491b608035137658d3524044e48e375cdac0472b9238d4
+Frame No. 017:
+ * input:  d9689ba5e3d260491b516adb5e4027256e27227ee0351c8e549a5c60492471971b
+ * output: d9689ba5e3d260491b516adb5e4027256e27227ee0351c8e549a5c60492471971b
+Frame No. 018:
+ * input:  (bad)
+ * output: d9689ba5e3d260491b516adb5e4027256e27227ee0351c8e549a5c60492471971b
+Frame No. 019:
+ * input:  (bad)
+ * output: d00000000000000000000000000000000000000000000000000000000000000000
+Frame No. 020:
+ * input:  d8e6a2e1d3d2605b1376c8d35280392451391cbc80392a71b6db8aa049238dc8ab
+ * output: d8e6a2e1d3d2605b1376c8d35280392451391cbc80392a71b6db8aa049238dc8ab
+Frame No. 021:
+ * input:  d9a87ba1a3982048eb8a471cac00472b4e391bbc40292489b71cc200495b8d3ae3
+ * output: d9a87ba1a3982048eb8a471cac00472b4e391bbc40292489b71cc200495b8d3ae3
+Frame No. 022:
+ * input:  d9278b2a1ba4c0475b8dc722d6e0491b5228da70204ae36dc71d94a056a29236e3
+ * output: d9278b2a1ba4c0475b8dc722d6e0491b5228da70204ae36dc71d94a056a29236e3
+Frame No. 023:
+ * input:  d9ec9be2129520392335598c50c04b5bad3d4ba680789b69df5a5aa0469cd1b4da
+ * output: d9ec9be2129520392335598c50c04b5bad3d4ba680789b69df5a5aa0469cd1b4da
+Frame No. 024:
+ * input:  d8ea932623e660669b8e4a9dd8a03aa32a76e466e028d396cc9bbe4047256dc8e5
+ * output: d8ea932623e660669b8e4a9dd8a03aa32a76e466e028d396cc9bbe4047256dc8e5
+Frame No. 025:
+ * input:  d96a94215aa0403aab713f22e8e024e68db91ab6a027abd1a55b6e804aec9146e4
+ * output: d96a94215aa0403aab713f22e8e024e68db91ab6a027abd1a55b6e804aec9146e4
+Frame No. 026:
+ * input:  d867ac21e270a0350d6ac91a724037247246d2a6c0396c89d6dc562049244e48d5
+ * output: d867ac21e270a0350d6ac91a724037247246d2a6c0396c89d6dc562049244e48d5
+Frame No. 027:
+ * input:  d8a9b460d3b48026a4ad471b7c20452491b69bbc803ae48db722ee00292491a8db
+ * output: d8a9b460d3b48026a4ad471b7c20452491b69bbc803ae48db722ee00292491a8db
+Frame No. 028:
+ * input:  d928a3e1d3b24036e37244abf02047634d371b74c047637148a29ac03b234e38e3
+ * output: d928a3e1d3b24036e37244abf02047634d371b74c047637148a29ac03b234e38e3
+Frame No. 029:
+ * input:  d9ab9b21d2e0c0471c693aec54e044dbae46dc7c20391badb724ee8038e469bb15
+ * output: d9ab9b21d2e0c0471c693aec54e044dbae46dc7c20391badb724ee8038e469bb15
+Frame No. 030:
+ * input:  d9a99361a276403b1a6ad6dcd40026e489c8e3bc40371c4dc564e2c036e28eb963
+ * output: d9a99361a276403b1a6ad6dcd40026e489c8e3bc40371c4dc564e2c036e28eb963
+Frame No. 031:
+ * input:  (bad)
+ * output: d9a99361a276403b1a6ad6dcd40026e489c8e3bc40371c4dc564e2c036e28eb963
+Frame No. 032:
+ * input:  (bad)
+ * output: d00000000000000000000000000000000000000000000000000000000000000000
+Frame No. 033:
+ * input:  (bad)
+ * output: d00000000000000000000000000000000000000000000000000000000000000000
+Frame No. 034:
+ * input:  (bad)
+ * output: d00000000000000000000000000000000000000000000000000000000000000000
+Frame No. 035:
+ * input:  (bad)
+ * output: d00000000000000000000000000000000000000000000000000000000000000000
+Frame No. 036:
+ * input:  (bad)
+ * output: d00000000000000000000000000000000000000000000000000000000000000000
+Frame No. 037:
+ * input:  d92c8b6d5aee4034ebb22724862047145634a5c0a038e371b8e4a880485c89dd25
+ * output: d92c8b6d5aee4034ebb22724862047145634a5c0a038e371b8e4a880485c89dd25
+Frame No. 038:
+ * input:  d8e78b29e3c6c038dba9d91beca04723ad491cda80471471b6ec7ae03b1396b91b
+ * output: d8e78b29e3c6c038dba9d91beca04723ad491cda80471471b6ec7ae03b1396b91b
+Frame No. 039:
+ * input:  d8a78b25e37a0022dd8a46dc68a0351bad391bde2046e56dd8dc96c038e396d89b
+ * output: d8a78b25e37a0022dd8a46dc68a0351bad391bde2046e56dd8dc96c038e396d89b
+Frame No. 040:
+ * input:  d8a88c255ab6e038e38e48dbde8038ad8dc8db8ec0376372b564b44038e49234dc
+ * output: d8a88c255ab6e038e38e48dbde8038ad8dc8db8ec0376372b564b44038e49234dc
+Frame No. 041:
+ * input:  d9708ce6a39ce049646646a2c1a0272496b29a66c037db562863ace0795b55b2e3
+ * output: d9708ce6a39ce049646646a2c1a0272496b29a66c037db562863ace0795b55b2e3
+Frame No. 042:
+ * input:  d8ee9bea5ae4003ae371b713eae05adc91995a5ea064dcc9571e786026ed51c52c
+ * output: d8ee9bea5ae4003ae371b713eae05adc91995a5ea064dcc9571e786026ed51c52c
+Frame No. 043:
+ * input:  d9299421d2944036ed69b8e572a048e36d551cd480571d4ec95be680356c69c763
+ * output: d9299421d2944036ed69b8e572a048e36d551cd480571d4ec95be680356c69c763
+Frame No. 044:
+ * input:  d92aab696190c046e26e392cae0026a376a8dc662048d291b75b54c04ad3ae3b1b
+ * output: d92aab696190c046e26e392cae0026a376a8dc662048d291b75b54c04ad3ae3b1b
+Frame No. 045:
+ * input:  d8e7a469627a6038e289cb1baca0569b8db6dddec026dc8e38e5dc803722722d23
+ * output: d8e7a469627a6038e289cb1baca0569b8db6dddec026dc8e38e5dc803722722d23
+Frame No. 046:
+ * input:  d8a88c299b64c03a548a58e37420272c6dd76b92c0471c9236dbc0e0551c71c713
+ * output: d8a88c299b64c03a548a58e37420272c6dd76b92c0471c9236dbc0e0551c71c713
+Frame No. 047:
+ * input:  (bad)
+ * output: d8a88c299b64c03a548a58e37420272c6dd76b92c0471c9236dbc0e0551c71c713
+Frame No. 048:
+ * input:  d7299c19a3be8024e58ea7a49f20a522963ad976e0a76ecd92b38500cb62aa4c94
+ * output: d7299c19a3be8024e58ea7a49f20a522963ad976e0a76ecd92b38500cb62aa4c94
+Frame No. 049:
+ * input:  d7eb6c6262eee02b2c42e79a60a0aa55aed68a7f00ad358e10fad960e55a39396d
+ * output: d7eb6c6262eee02b2c42e79a60a0aa55aed68a7f00ad358e10fad960e55a39396d
+Frame No. 050:
+ * input:  d970858dd2ab61d91355ebc15ca1a6a7ca48a05cc0dae66f2523c2a1bad3825daa
+ * output: d970858dd2ab61d91355ebc15ca1a6a7ca48a05cc0dae66f2523c2a1bad3825daa
+Frame No. 051:
+ * input:  d8f0844a23ad20da50d6de025e81c37392b9039cc0c764c1bd1e94c1b699736a98
+ * output: d8f0844a23ad20da50d6de025e81c37392b9039cc0c764c1bd1e94c1b699736a98
+Frame No. 052:
+ * input:  d9708ce6a39ce049646646a2c1a0272496b29a66c037db562863ace0795b55b2e3
+ * output: d9708ce6a39ce049646646a2c1a0272496b29a66c037db562863ace0795b55b2e3
+Frame No. 053:
+ * input:  d9299421d2944036ed69b8e572a048e36d551cd480571d4ec95be680356c69c763
+ * output: d9299421d2944036ed69b8e572a048e36d551cd480571d4ec95be680356c69c763
+Frame No. 054:
+ * input:  d9299421d2944036ed69b8e572a048e36d551cd480571d4ec95be680356c69c763
+ * output: d9299421d2944036ed69b8e572a048e36d551cd480571d4ec95be680356c69c763
+Frame No. 055:
+ * input:  d9299421d2944036ed69b8e572a048e36d551cd480571d4ec95be680356c69c763
+ * output: d9299421d2944036ed69b8e572a048e36d551cd480571d4ec95be680356c69c763
+Frame No. 056:
+ * input:  d2577a1cda50004924924924500049249249245000492492492450004923924924
+ * output: d2577a1cda50004924924924500049249249245000492492492450004923924924
+
+=> Testing FR concealment (realistic, using ECU abstraction)
 Frame No. 000:
  * input:  d9aa93ae63de00471a91b95b8660471392b4a2daa037628f391c624039258dc723
  * output: d9aa93ae63de00471a91b95b8660471392b4a2daa037628f391c624039258dc723