diff --git a/libavcodec/idcinvideo.c b/libavcodec/idcinvideo.c
index bdd71beef6..e10c173523 100644
--- a/libavcodec/idcinvideo.c
+++ b/libavcodec/idcinvideo.c
@@ -1,5 +1,5 @@
 /*
- * Id Quake II CIN Video Decoder
+ * id Quake II CIN Video Decoder
  * Copyright (C) 2003 the ffmpeg project
  *
  * This file is part of FFmpeg.
@@ -21,8 +21,8 @@
 
 /**
  * @file idcinvideo.c
- * Id Quake II Cin Video Decoder by Dr. Tim Ferguson
- * For more information about the Id CIN format, visit:
+ * id Quake II Cin Video Decoder by Dr. Tim Ferguson
+ * For more information about the id CIN format, visit:
  *   http://www.csse.monash.edu.au/~timf/
  *
  * This video decoder outputs PAL8 colorspace data. Interacting with this
@@ -32,7 +32,7 @@
  * the demuxer must use the same extradata space to transmit an
  * AVPaletteControl structure.
  *
- * Id CIN video is purely Huffman-coded, intraframe-only codec. It achieves
+ * id CIN video is purely Huffman-coded, intraframe-only codec. It achieves
  * a little more compression by exploiting the fact that adjacent pixels
  * tend to be similar.
  *
@@ -154,7 +154,7 @@ static av_cold int idcin_decode_init(AVCodecContext *avctx)
 
     /* make sure the Huffman tables make it */
     if (s->avctx->extradata_size != HUFFMAN_TABLE_SIZE) {
-        av_log(s->avctx, AV_LOG_ERROR, "  Id CIN video: expected extradata size of %d\n", HUFFMAN_TABLE_SIZE);
+        av_log(s->avctx, AV_LOG_ERROR, "  id CIN video: expected extradata size of %d\n", HUFFMAN_TABLE_SIZE);
         return -1;
     }
 
@@ -221,7 +221,7 @@ static int idcin_decode_frame(AVCodecContext *avctx,
         avctx->release_buffer(avctx, &s->frame);
 
     if (avctx->get_buffer(avctx, &s->frame)) {
-        av_log(avctx, AV_LOG_ERROR, "  Id CIN Video: get_buffer() failed\n");
+        av_log(avctx, AV_LOG_ERROR, "  id CIN Video: get_buffer() failed\n");
         return -1;
     }
 
@@ -262,6 +262,6 @@ AVCodec idcin_decoder = {
     idcin_decode_end,
     idcin_decode_frame,
     CODEC_CAP_DR1,
-    .long_name = "Id Quake II CIN video",
+    .long_name = "id Quake II CIN video",
 };
 
diff --git a/libavcodec/roqaudioenc.c b/libavcodec/roqaudioenc.c
index 65c9d78c8d..4546664b08 100644
--- a/libavcodec/roqaudioenc.c
+++ b/libavcodec/roqaudioenc.c
@@ -174,5 +174,5 @@ AVCodec roq_dpcm_encoder = {
     roq_dpcm_encode_frame,
     roq_dpcm_encode_close,
     NULL,
-    .long_name = "Id RoQ audio",
+    .long_name = "id RoQ audio",
 };
diff --git a/libavcodec/roqvideo.c b/libavcodec/roqvideo.c
index 53d60a19eb..e125a4c67a 100644
--- a/libavcodec/roqvideo.c
+++ b/libavcodec/roqvideo.c
@@ -21,7 +21,7 @@
 
 /**
  * @file roqvideo.c
- * Id RoQ Video common functions based on work by Dr. Tim Ferguson
+ * id RoQ Video common functions based on work by Dr. Tim Ferguson
  */
 
 #include "avcodec.h"
diff --git a/libavcodec/roqvideoenc.c b/libavcodec/roqvideoenc.c
index 667b821e11..e742938748 100644
--- a/libavcodec/roqvideoenc.c
+++ b/libavcodec/roqvideoenc.c
@@ -24,7 +24,7 @@
 
 /**
  * @file roqvideoenc.c
- * Id RoQ encoder by Vitor. Based on the Switchblade3 library and the
+ * id RoQ encoder by Vitor. Based on the Switchblade3 library and the
  * Switchblade3 FFmpeg glue by Eric Lasota.
  */
 
@@ -1066,5 +1066,5 @@ AVCodec roq_encoder =
     roq_encode_end,
     .supported_framerates = (AVRational[]){{30,1}, {0,0}},
     .pix_fmts = (enum PixelFormat[]){PIX_FMT_YUV444P, PIX_FMT_NONE},
-    .long_name = "Id RoQ video",
+    .long_name = "id RoQ video",
 };