avcodec/g729: add g729_parser

Add trivial g729 parser; fixes Ticket4753

Signed-off-by: Ganesh Ajjanagadde <gajjanagadde@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

libavcodec/Makefile

@@ -847,6 +847,7 @@ OBJS-$(CONFIG_DVD_NAV_PARSER)          += dvd_nav_parser.o
 OBJS-$(CONFIG_DVDSUB_PARSER)           += dvdsub_parser.o
 OBJS-$(CONFIG_FLAC_PARSER)             += flac_parser.o flacdata.o flac.o \
                                           vorbis_data.o
+OBJS-$(CONFIG_G729_PARSER)             += g729_parser.o
 OBJS-$(CONFIG_GSM_PARSER)              += gsm_parser.o
 OBJS-$(CONFIG_H261_PARSER)             += h261_parser.o
 OBJS-$(CONFIG_H263_PARSER)             += h263_parser.o

libavcodec/allcodecs.c

@@ -602,6 +602,7 @@ void avcodec_register_all(void)
     REGISTER_PARSER(DVDSUB,             dvdsub);
     REGISTER_PARSER(DVD_NAV,            dvd_nav);
     REGISTER_PARSER(FLAC,               flac);
+    REGISTER_PARSER(G729,               g729);
     REGISTER_PARSER(GSM,                gsm);
     REGISTER_PARSER(H261,               h261);
     REGISTER_PARSER(H263,               h263);

libavcodec/g729.h

@@ -26,4 +26,8 @@
  */
 #define SUBFRAME_SIZE 40
 
+/* bytes per block */
+#define G729_8K_BLOCK_SIZE     10
+#define G729D_6K4_BLOCK_SIZE   8
+
 #endif // AVCODEC_G729_H

libavcodec/g729_parser.c

@@ -0,0 +1,89 @@
+/*
+ * Copyright (c) 2015  Ganesh Ajjanagadde
+ *
+ * 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
+ * G.729 audio parser
+ *
+ * Splits packets into individual blocks.
+ */
+
+#include "parser.h"
+#include "g729.h"
+
+typedef struct G729ParseContext {
+    ParseContext pc;
+    int block_size;
+    int duration;
+    int remaining;
+} G729ParseContext;
+
+static int g729_parse(AVCodecParserContext *s1, AVCodecContext *avctx,
+                     const uint8_t **poutbuf, int *poutbuf_size,
+                     const uint8_t *buf, int buf_size)
+{
+    G729ParseContext *s = s1->priv_data;
+    ParseContext *pc = &s->pc;
+    int next;
+
+    if (!s->block_size) {
+        switch (avctx->codec_id) {
+        case AV_CODEC_ID_G729:
+            /* FIXME: replace this heuristic block_size with more precise estimate */
+            s->block_size = (avctx->bit_rate < 8000) ? G729D_6K4_BLOCK_SIZE : G729_8K_BLOCK_SIZE;
+            s->duration   = avctx->frame_size;
+            break;
+        default:
+            *poutbuf      = buf;
+            *poutbuf_size = buf_size;
+            av_log(avctx, AV_LOG_ERROR, "Invalid codec_id\n");
+            return buf_size;
+        }
+    }
+
+    if (!s->remaining)
+        s->remaining = s->block_size;
+    if (s->remaining <= buf_size) {
+        next = s->remaining;
+        s->remaining = 0;
+    } else {
+        next = END_NOT_FOUND;
+        s->remaining -= buf_size;
+    }
+
+    if (ff_combine_frame(pc, next, &buf, &buf_size) < 0 || !buf_size) {
+        *poutbuf      = NULL;
+        *poutbuf_size = 0;
+        return buf_size;
+    }
+
+    s1->duration = s->duration;
+
+    *poutbuf      = buf;
+    *poutbuf_size = buf_size;
+    return next;
+}
+
+AVCodecParser ff_g729_parser = {
+    .codec_ids      = { AV_CODEC_ID_G729 },
+    .priv_data_size = sizeof(G729ParseContext),
+    .parser_parse   = g729_parse,
+    .parser_close   = ff_parse_close,
+};