libavformat/mpc.c - third_party/ffmpeg - Git at Google

 /*
  * Musepack demuxer
  * Copyright (c) 2006 Konstantin Shishkov
  *
  * 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 "internal.h"
 #include "apetag.h"
 #include "id3v1.h"
 #include "libavutil/dict.h"

 #define MPC_FRAMESIZE  1152
 #define DELAY_FRAMES   32

 static const int mpc_rate[4] = { 44100, 48000, 37800, 32000 };
 typedef struct MPCFrame {
     int64_t pos;
     int size, skip;
 }MPCFrame;

 typedef struct MPCContext {
     int ver;
     uint32_t curframe, lastframe;
     uint32_t fcount;
     MPCFrame *frames;
     int curbits;
     int frames_noted;
 } MPCContext;

 static int mpc_probe(const AVProbeData *p)
 {
     const uint8_t *d = p->buf;
     if (d[0] == 'M' && d[1] == 'P' && d[2] == '+' && (d[3] == 0x17 || d[3] == 0x7))
         return AVPROBE_SCORE_MAX;
     return 0;
 }

 static int mpc_read_header(AVFormatContext *s)
 {
     MPCContext *c = s->priv_data;
     AVStream *st;

     if(avio_rl24(s->pb) != MKTAG('M', 'P', '+', 0)){
         av_log(s, AV_LOG_ERROR, "Not a Musepack file\n");
         return AVERROR_INVALIDDATA;
     }
     c->ver = avio_r8(s->pb);
     if(c->ver != 0x07 && c->ver != 0x17){
         av_log(s, AV_LOG_ERROR, "Can demux Musepack SV7, got version %02X\n", c->ver);
         return AVERROR_INVALIDDATA;
     }
     c->fcount = avio_rl32(s->pb);
     if((int64_t)c->fcount * sizeof(MPCFrame) >= UINT_MAX){
         av_log(s, AV_LOG_ERROR, "Too many frames, seeking is not possible\n");
         return AVERROR_INVALIDDATA;
     }
     if(c->fcount){
         c->frames = av_malloc(c->fcount * sizeof(MPCFrame));
         if(!c->frames){
             av_log(s, AV_LOG_ERROR, "Cannot allocate seektable\n");
             return AVERROR(ENOMEM);
         }
     }else{
         av_log(s, AV_LOG_WARNING, "Container reports no frames\n");
     }
     c->curframe = 0;
     c->lastframe = -1;
     c->curbits = 8;
     c->frames_noted = 0;

     st = avformat_new_stream(s, NULL);
     if (!st)
         goto mem_error;
     st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
     st->codecpar->codec_id = AV_CODEC_ID_MUSEPACK7;
     st->codecpar->channels = 2;
     st->codecpar->channel_layout = AV_CH_LAYOUT_STEREO;
     st->codecpar->bits_per_coded_sample = 16;

     if (ff_get_extradata(s, st->codecpar, s->pb, 16) < 0)
         goto mem_error;
     st->codecpar->sample_rate = mpc_rate[st->codecpar->extradata[2] & 3];
     avpriv_set_pts_info(st, 32, MPC_FRAMESIZE, st->codecpar->sample_rate);
     /* scan for seekpoints */
     st->start_time = 0;
     st->duration = c->fcount;

     /* try to read APE tags */
     if (s->pb->seekable & AVIO_SEEKABLE_NORMAL) {
         int64_t pos = avio_tell(s->pb);
         ff_ape_parse_tag(s);
         if (!av_dict_get(s->metadata, "", NULL, AV_DICT_IGNORE_SUFFIX))
             ff_id3v1_read(s);
         avio_seek(s->pb, pos, SEEK_SET);
     }

     return 0;
 mem_error:
     av_freep(&c->frames);
     return AVERROR(ENOMEM);
 }

 static int mpc_read_packet(AVFormatContext *s, AVPacket *pkt)
 {
     MPCContext *c = s->priv_data;
     int ret, size, size2, curbits, cur = c->curframe;
     unsigned tmp;
     int64_t pos;

     if (c->curframe >= c->fcount && c->fcount)
         return AVERROR_EOF;

     if(c->curframe != c->lastframe + 1){
         avio_seek(s->pb, c->frames[c->curframe].pos, SEEK_SET);
         c->curbits = c->frames[c->curframe].skip;
     }
     c->lastframe = c->curframe;
     c->curframe++;
     curbits = c->curbits;
     pos = avio_tell(s->pb);
     tmp = avio_rl32(s->pb);
     if(curbits <= 12){
         size2 = (tmp >> (12 - curbits)) & 0xFFFFF;
     }else{
         size2 = (tmp << (curbits - 12) | avio_rl32(s->pb) >> (44 - curbits)) & 0xFFFFF;
     }
     curbits += 20;
     avio_seek(s->pb, pos, SEEK_SET);

     size = ((size2 + curbits + 31) & ~31) >> 3;
     if(cur == c->frames_noted && c->fcount){
         c->frames[cur].pos = pos;
         c->frames[cur].size = size;
         c->frames[cur].skip = curbits - 20;
         av_add_index_entry(s->streams[0], cur, cur, size, 0, AVINDEX_KEYFRAME);
         c->frames_noted++;
     }
     c->curbits = (curbits + size2) & 0x1F;

     if ((ret = av_new_packet(pkt, size + 4)) < 0)
         return ret;

     pkt->data[0] = curbits;
     pkt->data[1] = (c->curframe > c->fcount) && c->fcount;
     pkt->data[2] = 0;
     pkt->data[3] = 0;

     pkt->stream_index = 0;
     pkt->pts = cur;
     ret = avio_read(s->pb, pkt->data + 4, size);
     if(c->curbits)
         avio_seek(s->pb, -4, SEEK_CUR);
     if(ret < size){
         av_packet_unref(pkt);
         return ret < 0 ? ret : AVERROR(EIO);
     }
     pkt->size = ret + 4;

     return 0;
 }

 static int mpc_read_close(AVFormatContext *s)
 {
     MPCContext *c = s->priv_data;

     av_freep(&c->frames);
     return 0;
 }

 /**
  * Seek to the given position
  * If position is unknown but is within the limits of file
  * then packets are skipped unless desired position is reached
  *
  * Also this function makes use of the fact that timestamp == frameno
  */
 static int mpc_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
 {
     AVStream *st = s->streams[stream_index];
     MPCContext *c = s->priv_data;
     AVPacket pkt1, *pkt = &pkt1;
     int ret;
     int index = av_index_search_timestamp(st, FFMAX(timestamp - DELAY_FRAMES, 0), flags);
     uint32_t lastframe;

     /* if found, seek there */
     if (index >= 0 && st->index_entries[st->nb_index_entries-1].timestamp >= timestamp - DELAY_FRAMES){
         c->curframe = st->index_entries[index].pos;
         return 0;
     }
     /* if timestamp is out of bounds, return error */
     if(timestamp < 0 || timestamp >= c->fcount)
         return -1;
     timestamp -= DELAY_FRAMES;
     /* seek to the furthest known position and read packets until
        we reach desired position */
     lastframe = c->curframe;
     if(c->frames_noted) c->curframe = c->frames_noted - 1;
     while(c->curframe < timestamp){
         ret = av_read_frame(s, pkt);
         if (ret < 0){
             c->curframe = lastframe;
             return ret;
         }
         av_packet_unref(pkt);
     }
     return 0;
 }


 AVInputFormat ff_mpc_demuxer = {
     .name           = "mpc",
     .long_name      = NULL_IF_CONFIG_SMALL("Musepack"),
     .priv_data_size = sizeof(MPCContext),
     .read_probe     = mpc_probe,
     .read_header    = mpc_read_header,
     .read_packet    = mpc_read_packet,
     .read_close     = mpc_read_close,
     .read_seek      = mpc_read_seek,
     .extensions     = "mpc",
 };
	/*
	* Musepack demuxer
	* Copyright (c) 2006 Konstantin Shishkov
	*
	* 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 "internal.h"
	#include "apetag.h"
	#include "id3v1.h"
	#include "libavutil/dict.h"

	#define MPC_FRAMESIZE 1152
	#define DELAY_FRAMES 32

	static const int mpc_rate[4] = { 44100, 48000, 37800, 32000 };
	typedef struct MPCFrame {
	int64_t pos;
	int size, skip;
	}MPCFrame;

	typedef struct MPCContext {
	int ver;
	uint32_t curframe, lastframe;
	uint32_t fcount;
	MPCFrame *frames;
	int curbits;
	int frames_noted;
	} MPCContext;

	static int mpc_probe(const AVProbeData *p)
	{
	const uint8_t *d = p->buf;
	if (d[0] == 'M' && d[1] == 'P' && d[2] == '+' && (d[3] == 0x17 \|\| d[3] == 0x7))
	return AVPROBE_SCORE_MAX;
	return 0;
	}

	static int mpc_read_header(AVFormatContext *s)
	{
	MPCContext *c = s->priv_data;
	AVStream *st;

	if(avio_rl24(s->pb) != MKTAG('M', 'P', '+', 0)){
	av_log(s, AV_LOG_ERROR, "Not a Musepack file\n");
	return AVERROR_INVALIDDATA;
	}
	c->ver = avio_r8(s->pb);
	if(c->ver != 0x07 && c->ver != 0x17){
	av_log(s, AV_LOG_ERROR, "Can demux Musepack SV7, got version %02X\n", c->ver);
	return AVERROR_INVALIDDATA;
	}
	c->fcount = avio_rl32(s->pb);
	if((int64_t)c->fcount * sizeof(MPCFrame) >= UINT_MAX){
	av_log(s, AV_LOG_ERROR, "Too many frames, seeking is not possible\n");
	return AVERROR_INVALIDDATA;
	}
	if(c->fcount){
	c->frames = av_malloc(c->fcount * sizeof(MPCFrame));
	if(!c->frames){
	av_log(s, AV_LOG_ERROR, "Cannot allocate seektable\n");
	return AVERROR(ENOMEM);
	}
	}else{
	av_log(s, AV_LOG_WARNING, "Container reports no frames\n");
	}
	c->curframe = 0;
	c->lastframe = -1;
	c->curbits = 8;
	c->frames_noted = 0;

	st = avformat_new_stream(s, NULL);
	if (!st)
	goto mem_error;
	st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
	st->codecpar->codec_id = AV_CODEC_ID_MUSEPACK7;
	st->codecpar->channels = 2;
	st->codecpar->channel_layout = AV_CH_LAYOUT_STEREO;
	st->codecpar->bits_per_coded_sample = 16;

	if (ff_get_extradata(s, st->codecpar, s->pb, 16) < 0)
	goto mem_error;
	st->codecpar->sample_rate = mpc_rate[st->codecpar->extradata[2] & 3];
	avpriv_set_pts_info(st, 32, MPC_FRAMESIZE, st->codecpar->sample_rate);
	/* scan for seekpoints */
	st->start_time = 0;
	st->duration = c->fcount;

	/* try to read APE tags */
	if (s->pb->seekable & AVIO_SEEKABLE_NORMAL) {
	int64_t pos = avio_tell(s->pb);
	ff_ape_parse_tag(s);
	if (!av_dict_get(s->metadata, "", NULL, AV_DICT_IGNORE_SUFFIX))
	ff_id3v1_read(s);
	avio_seek(s->pb, pos, SEEK_SET);
	}

	return 0;
	mem_error:
	av_freep(&c->frames);
	return AVERROR(ENOMEM);
	}

	static int mpc_read_packet(AVFormatContext s, AVPacket pkt)
	{
	MPCContext *c = s->priv_data;
	int ret, size, size2, curbits, cur = c->curframe;
	unsigned tmp;
	int64_t pos;

	if (c->curframe >= c->fcount && c->fcount)
	return AVERROR_EOF;

	if(c->curframe != c->lastframe + 1){
	avio_seek(s->pb, c->frames[c->curframe].pos, SEEK_SET);
	c->curbits = c->frames[c->curframe].skip;
	}
	c->lastframe = c->curframe;
	c->curframe++;
	curbits = c->curbits;
	pos = avio_tell(s->pb);
	tmp = avio_rl32(s->pb);
	if(curbits <= 12){
	size2 = (tmp >> (12 - curbits)) & 0xFFFFF;
	}else{
	size2 = (tmp << (curbits - 12) \| avio_rl32(s->pb) >> (44 - curbits)) & 0xFFFFF;
	}
	curbits += 20;
	avio_seek(s->pb, pos, SEEK_SET);

	size = ((size2 + curbits + 31) & ~31) >> 3;
	if(cur == c->frames_noted && c->fcount){
	c->frames[cur].pos = pos;
	c->frames[cur].size = size;
	c->frames[cur].skip = curbits - 20;
	av_add_index_entry(s->streams[0], cur, cur, size, 0, AVINDEX_KEYFRAME);
	c->frames_noted++;
	}
	c->curbits = (curbits + size2) & 0x1F;

	if ((ret = av_new_packet(pkt, size + 4)) < 0)
	return ret;

	pkt->data[0] = curbits;
	pkt->data[1] = (c->curframe > c->fcount) && c->fcount;
	pkt->data[2] = 0;
	pkt->data[3] = 0;

	pkt->stream_index = 0;
	pkt->pts = cur;
	ret = avio_read(s->pb, pkt->data + 4, size);
	if(c->curbits)
	avio_seek(s->pb, -4, SEEK_CUR);
	if(ret < size){
	av_packet_unref(pkt);
	return ret < 0 ? ret : AVERROR(EIO);
	}
	pkt->size = ret + 4;

	return 0;
	}

	static int mpc_read_close(AVFormatContext *s)
	{
	MPCContext *c = s->priv_data;

	av_freep(&c->frames);
	return 0;
	}

	/**
	* Seek to the given position
	* If position is unknown but is within the limits of file
	* then packets are skipped unless desired position is reached
	*
	* Also this function makes use of the fact that timestamp == frameno
	*/
	static int mpc_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
	{
	AVStream *st = s->streams[stream_index];
	MPCContext *c = s->priv_data;
	AVPacket pkt1, *pkt = &pkt1;
	int ret;
	int index = av_index_search_timestamp(st, FFMAX(timestamp - DELAY_FRAMES, 0), flags);
	uint32_t lastframe;

	/* if found, seek there */
	if (index >= 0 && st->index_entries[st->nb_index_entries-1].timestamp >= timestamp - DELAY_FRAMES){
	c->curframe = st->index_entries[index].pos;
	return 0;
	}
	/* if timestamp is out of bounds, return error */
	if(timestamp < 0 \|\| timestamp >= c->fcount)
	return -1;
	timestamp -= DELAY_FRAMES;
	/* seek to the furthest known position and read packets until
	we reach desired position */
	lastframe = c->curframe;
	if(c->frames_noted) c->curframe = c->frames_noted - 1;
	while(c->curframe < timestamp){
	ret = av_read_frame(s, pkt);
	if (ret < 0){
	c->curframe = lastframe;
	return ret;
	}
	av_packet_unref(pkt);
	}
	return 0;
	}


	AVInputFormat ff_mpc_demuxer = {
	.name = "mpc",
	.long_name = NULL_IF_CONFIG_SMALL("Musepack"),
	.priv_data_size = sizeof(MPCContext),
	.read_probe = mpc_probe,
	.read_header = mpc_read_header,
	.read_packet = mpc_read_packet,
	.read_close = mpc_read_close,
	.read_seek = mpc_read_seek,
	.extensions = "mpc",
	};