[FFmpeg-devel] [PATCH 1/3] avcodec: add XMA2 parser

Paul B Mahol onemda at gmail.com
Thu Jan 19 22:05:04 EET 2017


Signed-off-by: Paul B Mahol <onemda at gmail.com>
---
 libavcodec/Makefile     |  1 +
 libavcodec/allcodecs.c  |  1 +
 libavcodec/xma_parser.c | 62 +++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 64 insertions(+)
 create mode 100644 libavcodec/xma_parser.c

diff --git a/libavcodec/Makefile b/libavcodec/Makefile
index 01ffe07..43a6add 100644
--- a/libavcodec/Makefile
+++ b/libavcodec/Makefile
@@ -950,6 +950,7 @@ OBJS-$(CONFIG_VC1_PARSER)              += vc1_parser.o vc1.o vc1data.o  \
 OBJS-$(CONFIG_VP3_PARSER)              += vp3_parser.o
 OBJS-$(CONFIG_VP8_PARSER)              += vp8_parser.o
 OBJS-$(CONFIG_VP9_PARSER)              += vp9_parser.o
+OBJS-$(CONFIG_XMA_PARSER)              += xma_parser.o
 
 # bitstream filters
 OBJS-$(CONFIG_AAC_ADTSTOASC_BSF)          += aac_adtstoasc_bsf.o aacadtsdec.o \
diff --git a/libavcodec/allcodecs.c b/libavcodec/allcodecs.c
index 703c552..f92b2b7 100644
--- a/libavcodec/allcodecs.c
+++ b/libavcodec/allcodecs.c
@@ -709,4 +709,5 @@ void avcodec_register_all(void)
     REGISTER_PARSER(VP3,                vp3);
     REGISTER_PARSER(VP8,                vp8);
     REGISTER_PARSER(VP9,                vp9);
+    REGISTER_PARSER(XMA,                xma);
 }
diff --git a/libavcodec/xma_parser.c b/libavcodec/xma_parser.c
new file mode 100644
index 0000000..0513679
--- /dev/null
+++ b/libavcodec/xma_parser.c
@@ -0,0 +1,62 @@
+/*
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/**
+ * @file
+ * XMA2 audio parser
+ */
+
+#include "parser.h"
+
+typedef struct XMAParserContext{
+    int skip_packets;
+} XMAParserContext;
+
+static int xma_parse(AVCodecParserContext *s1, AVCodecContext *avctx,
+                     const uint8_t **poutbuf, int *poutbuf_size,
+                     const uint8_t *buf, int buf_size)
+{
+    XMAParserContext *s = s1->priv_data;
+
+    if (buf_size % 2048 == 0) {
+        int duration = 0, packet, nb_packets = buf_size / 2048;
+
+        for (packet = 0; packet < nb_packets; packet++) {
+            if (s->skip_packets == 0) {
+                duration += buf[packet * 2048] * 128;
+                s->skip_packets = buf[packet * 2048 + 3] + 1;
+            }
+            s->skip_packets--;
+        }
+
+        s1->duration = duration;
+        s1->key_frame = !!duration;
+    }
+
+    /* always return the full packet. this parser isn't doing any splitting or
+       combining, only packet analysis */
+    *poutbuf      = buf;
+    *poutbuf_size = buf_size;
+    return buf_size;
+}
+
+AVCodecParser ff_xma_parser = {
+    .codec_ids      = { AV_CODEC_ID_XMA2 },
+    .priv_data_size = sizeof(XMAParserContext),
+    .parser_parse   = xma_parse,
+};
-- 
2.9.3



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