libavformat/rtpdec_amr.c - nest-android-app/ffmpeg - Git at Google

 /*
  * RTP AMR Depacketizer, RFC 3267
  * Copyright (c) 2010 Martin Storsjo
  *
  * 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
  */

 #include "libavutil/channel_layout.h"
 #include "avformat.h"
 #include "rtpdec_formats.h"
 #include "libavutil/avstring.h"

 static const uint8_t frame_sizes_nb[16] = {
     12, 13, 15, 17, 19, 20, 26, 31, 5, 0, 0, 0, 0, 0, 0, 0
 };
 static const uint8_t frame_sizes_wb[16] = {
     17, 23, 32, 36, 40, 46, 50, 58, 60, 5, 5, 0, 0, 0, 0, 0
 };

 struct PayloadContext {
     int octet_align;
     int crc;
     int interleaving;
     int channels;
 };

 static av_cold int amr_init(AVFormatContext *s, int st_index, PayloadContext *data)
 {
     data->channels = 1;
     return 0;
 }

 static int amr_handle_packet(AVFormatContext *ctx, PayloadContext *data,
                              AVStream *st, AVPacket *pkt, uint32_t *timestamp,
                              const uint8_t *buf, int len, uint16_t seq,
                              int flags)
 {
     const uint8_t *frame_sizes = NULL;
     int frames;
     int i;
     const uint8_t *speech_data;
     uint8_t *ptr;

     if (st->codec->codec_id == AV_CODEC_ID_AMR_NB) {
         frame_sizes = frame_sizes_nb;
     } else if (st->codec->codec_id == AV_CODEC_ID_AMR_WB) {
         frame_sizes = frame_sizes_wb;
     } else {
         av_log(ctx, AV_LOG_ERROR, "Bad codec ID\n");
         return AVERROR_INVALIDDATA;
     }

     if (st->codec->channels != 1) {
         av_log(ctx, AV_LOG_ERROR, "Only mono AMR is supported\n");
         return AVERROR_INVALIDDATA;
     }
     st->codec->channel_layout = AV_CH_LAYOUT_MONO;

     /* The AMR RTP packet consists of one header byte, followed
      * by one TOC byte for each AMR frame in the packet, followed
      * by the speech data for all the AMR frames.
      *
      * The header byte contains only a codec mode request, for
      * requesting what kind of AMR data the sender wants to
      * receive. Not used at the moment.
      */

     /* Count the number of frames in the packet. The highest bit
      * is set in a TOC byte if there are more frames following.
      */
     for (frames = 1; frames < len && (buf[frames] & 0x80); frames++) ;

     if (1 + frames >= len) {
         /* We hit the end of the packet while counting frames. */
         av_log(ctx, AV_LOG_ERROR, "No speech data found\n");
         return AVERROR_INVALIDDATA;
     }

     speech_data = buf + 1 + frames;

     /* Everything except the codec mode request byte should be output. */
     if (av_new_packet(pkt, len - 1)) {
         av_log(ctx, AV_LOG_ERROR, "Out of memory\n");
         return AVERROR(ENOMEM);
     }
     pkt->stream_index = st->index;
     ptr = pkt->data;

     for (i = 0; i < frames; i++) {
         uint8_t toc = buf[1 + i];
         int frame_size = frame_sizes[(toc >> 3) & 0x0f];

         if (speech_data + frame_size > buf + len) {
             /* Too little speech data */
             av_log(ctx, AV_LOG_WARNING, "Too little speech data in the RTP packet\n");
             /* Set the unwritten part of the packet to zero. */
             memset(ptr, 0, pkt->data + pkt->size - ptr);
             pkt->size = ptr - pkt->data;
             return 0;
         }

         /* Extract the AMR frame mode from the TOC byte */
         *ptr++ = toc & 0x7C;

         /* Copy the speech data */
         memcpy(ptr, speech_data, frame_size);
         speech_data += frame_size;
         ptr += frame_size;
     }

     if (speech_data < buf + len) {
         av_log(ctx, AV_LOG_WARNING, "Too much speech data in the RTP packet?\n");
         /* Set the unwritten part of the packet to zero. */
         memset(ptr, 0, pkt->data + pkt->size - ptr);
         pkt->size = ptr - pkt->data;
     }

     return 0;
 }

 static int amr_parse_fmtp(AVFormatContext *s,
                           AVStream *stream, PayloadContext *data,
                           const char *attr, const char *value)
 {
     /* Some AMR SDP configurations contain "octet-align", without
      * the trailing =1. Therefore, if the value is empty,
      * interpret it as "1".
      */
     if (!strcmp(value, "")) {
         av_log(s, AV_LOG_WARNING, "AMR fmtp attribute %s had "
                                   "nonstandard empty value\n", attr);
         value = "1";
     }
     if (!strcmp(attr, "octet-align"))
         data->octet_align = atoi(value);
     else if (!strcmp(attr, "crc"))
         data->crc = atoi(value);
     else if (!strcmp(attr, "interleaving"))
         data->interleaving = atoi(value);
     else if (!strcmp(attr, "channels"))
         data->channels = atoi(value);
     return 0;
 }

 static int amr_parse_sdp_line(AVFormatContext *s, int st_index,
                               PayloadContext *data, const char *line)
 {
     const char *p;
     int ret;

     if (st_index < 0)
         return 0;

     /* Parse an fmtp line this one:
      * a=fmtp:97 octet-align=1; interleaving=0
      * That is, a normal fmtp: line followed by semicolon & space
      * separated key/value pairs.
      */
     if (av_strstart(line, "fmtp:", &p)) {
         ret = ff_parse_fmtp(s, s->streams[st_index], data, p, amr_parse_fmtp);
         if (!data->octet_align || data->crc ||
             data->interleaving || data->channels != 1) {
             av_log(s, AV_LOG_ERROR, "Unsupported RTP/AMR configuration!\n");
             return -1;
         }
         return ret;
     }
     return 0;
 }

 RTPDynamicProtocolHandler ff_amr_nb_dynamic_handler = {
     .enc_name         = "AMR",
     .codec_type       = AVMEDIA_TYPE_AUDIO,
     .codec_id         = AV_CODEC_ID_AMR_NB,
     .priv_data_size   = sizeof(PayloadContext),
     .init             = amr_init,
     .parse_sdp_a_line = amr_parse_sdp_line,
     .parse_packet     = amr_handle_packet,
 };

 RTPDynamicProtocolHandler ff_amr_wb_dynamic_handler = {
     .enc_name         = "AMR-WB",
     .codec_type       = AVMEDIA_TYPE_AUDIO,
     .codec_id         = AV_CODEC_ID_AMR_WB,
     .priv_data_size   = sizeof(PayloadContext),
     .init             = amr_init,
     .parse_sdp_a_line = amr_parse_sdp_line,
     .parse_packet     = amr_handle_packet,
 };
	/*
	* RTP AMR Depacketizer, RFC 3267
	* Copyright (c) 2010 Martin Storsjo
	*
	* 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
	*/

	#include "libavutil/channel_layout.h"
	#include "avformat.h"
	#include "rtpdec_formats.h"
	#include "libavutil/avstring.h"

	static const uint8_t frame_sizes_nb[16] = {
	12, 13, 15, 17, 19, 20, 26, 31, 5, 0, 0, 0, 0, 0, 0, 0
	};
	static const uint8_t frame_sizes_wb[16] = {
	17, 23, 32, 36, 40, 46, 50, 58, 60, 5, 5, 0, 0, 0, 0, 0
	};

	struct PayloadContext {
	int octet_align;
	int crc;
	int interleaving;
	int channels;
	};

	static av_cold int amr_init(AVFormatContext s, int st_index, PayloadContext data)
	{
	data->channels = 1;
	return 0;
	}

	static int amr_handle_packet(AVFormatContext ctx, PayloadContext data,
	AVStream st, AVPacket pkt, uint32_t *timestamp,
	const uint8_t *buf, int len, uint16_t seq,
	int flags)
	{
	const uint8_t *frame_sizes = NULL;
	int frames;
	int i;
	const uint8_t *speech_data;
	uint8_t *ptr;

	if (st->codec->codec_id == AV_CODEC_ID_AMR_NB) {
	frame_sizes = frame_sizes_nb;
	} else if (st->codec->codec_id == AV_CODEC_ID_AMR_WB) {
	frame_sizes = frame_sizes_wb;
	} else {
	av_log(ctx, AV_LOG_ERROR, "Bad codec ID\n");
	return AVERROR_INVALIDDATA;
	}

	if (st->codec->channels != 1) {
	av_log(ctx, AV_LOG_ERROR, "Only mono AMR is supported\n");
	return AVERROR_INVALIDDATA;
	}
	st->codec->channel_layout = AV_CH_LAYOUT_MONO;

	/* The AMR RTP packet consists of one header byte, followed
	* by one TOC byte for each AMR frame in the packet, followed
	* by the speech data for all the AMR frames.
	*
	* The header byte contains only a codec mode request, for
	* requesting what kind of AMR data the sender wants to
	* receive. Not used at the moment.
	*/

	/* Count the number of frames in the packet. The highest bit
	* is set in a TOC byte if there are more frames following.
	*/
	for (frames = 1; frames < len && (buf[frames] & 0x80); frames++) ;

	if (1 + frames >= len) {
	/* We hit the end of the packet while counting frames. */
	av_log(ctx, AV_LOG_ERROR, "No speech data found\n");
	return AVERROR_INVALIDDATA;
	}

	speech_data = buf + 1 + frames;

	/* Everything except the codec mode request byte should be output. */
	if (av_new_packet(pkt, len - 1)) {
	av_log(ctx, AV_LOG_ERROR, "Out of memory\n");
	return AVERROR(ENOMEM);
	}
	pkt->stream_index = st->index;
	ptr = pkt->data;

	for (i = 0; i < frames; i++) {
	uint8_t toc = buf[1 + i];
	int frame_size = frame_sizes[(toc >> 3) & 0x0f];

	if (speech_data + frame_size > buf + len) {
	/* Too little speech data */
	av_log(ctx, AV_LOG_WARNING, "Too little speech data in the RTP packet\n");
	/* Set the unwritten part of the packet to zero. */
	memset(ptr, 0, pkt->data + pkt->size - ptr);
	pkt->size = ptr - pkt->data;
	return 0;
	}

	/* Extract the AMR frame mode from the TOC byte */
	*ptr++ = toc & 0x7C;

	/* Copy the speech data */
	memcpy(ptr, speech_data, frame_size);
	speech_data += frame_size;
	ptr += frame_size;
	}

	if (speech_data < buf + len) {
	av_log(ctx, AV_LOG_WARNING, "Too much speech data in the RTP packet?\n");
	/* Set the unwritten part of the packet to zero. */
	memset(ptr, 0, pkt->data + pkt->size - ptr);
	pkt->size = ptr - pkt->data;
	}

	return 0;
	}

	static int amr_parse_fmtp(AVFormatContext *s,
	AVStream stream, PayloadContext data,
	const char attr, const char value)
	{
	/* Some AMR SDP configurations contain "octet-align", without
	* the trailing =1. Therefore, if the value is empty,
	* interpret it as "1".
	*/
	if (!strcmp(value, "")) {
	av_log(s, AV_LOG_WARNING, "AMR fmtp attribute %s had "
	"nonstandard empty value\n", attr);
	value = "1";
	}
	if (!strcmp(attr, "octet-align"))
	data->octet_align = atoi(value);
	else if (!strcmp(attr, "crc"))
	data->crc = atoi(value);
	else if (!strcmp(attr, "interleaving"))
	data->interleaving = atoi(value);
	else if (!strcmp(attr, "channels"))
	data->channels = atoi(value);
	return 0;
	}

	static int amr_parse_sdp_line(AVFormatContext *s, int st_index,
	PayloadContext data, const char line)
	{
	const char *p;
	int ret;

	if (st_index < 0)
	return 0;

	/* Parse an fmtp line this one:
	* a=fmtp:97 octet-align=1; interleaving=0
	* That is, a normal fmtp: line followed by semicolon & space
	* separated key/value pairs.
	*/
	if (av_strstart(line, "fmtp:", &p)) {
	ret = ff_parse_fmtp(s, s->streams[st_index], data, p, amr_parse_fmtp);
	if (!data->octet_align \|\| data->crc \|\|
	data->interleaving \|\| data->channels != 1) {
	av_log(s, AV_LOG_ERROR, "Unsupported RTP/AMR configuration!\n");
	return -1;
	}
	return ret;
	}
	return 0;
	}

	RTPDynamicProtocolHandler ff_amr_nb_dynamic_handler = {
	.enc_name = "AMR",
	.codec_type = AVMEDIA_TYPE_AUDIO,
	.codec_id = AV_CODEC_ID_AMR_NB,
	.priv_data_size = sizeof(PayloadContext),
	.init = amr_init,
	.parse_sdp_a_line = amr_parse_sdp_line,
	.parse_packet = amr_handle_packet,
	};

	RTPDynamicProtocolHandler ff_amr_wb_dynamic_handler = {
	.enc_name = "AMR-WB",
	.codec_type = AVMEDIA_TYPE_AUDIO,
	.codec_id = AV_CODEC_ID_AMR_WB,
	.priv_data_size = sizeof(PayloadContext),
	.init = amr_init,
	.parse_sdp_a_line = amr_parse_sdp_line,
	.parse_packet = amr_handle_packet,
	};