mpv/libmpdemux/demux_mng.c

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/*
* MNG file demuxer for MPlayer
*
* Copyright (C) 2008 Stefan Schuermans <stefan blinkenarea org>
*
* This file is part of MPlayer.
*
* MPlayer is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* MPlayer 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with MPlayer; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include "config.h"
#include "mp_msg.h"
#include "stream/stream.h"
#include "demuxer.h"
#include "stheader.h"
#define MNG_SUPPORT_READ
#define MNG_SUPPORT_DISPLAY
#include <libmng.h>
/**
* \brief some small fixed start time > 0
*
* Start time must be > 0 for the variable frame time mechanism
* (GIF, MATROSKA, MNG) in video.c to work for the first frame.
*/
#define MNG_START_PTS 0.01f
/**
* \brief private context structure
*
* This structure is used as private data for MPlayer demuxer
* and also as private data for the MNG library.
*
* All members ending in \p _ms are in milliseconds
*/
typedef struct {
stream_t * stream; ///< pointer to MNG data input stream
mng_handle h_mng; ///< MNG library image handle
int header_processed; ///< if MNG image header is processed
mng_uint32 width; ///< MNG image width
mng_uint32 height; ///< MNG image height
int total_time_ms; ///< total MNG animation time
unsigned char * canvas; /**< \brief canvas to draw the image onto
* \details
* \li lines top-down
* \li pixels left-to-right
* \li channels RGB
* \li no padding
* \li NULL if no canvas yet
*/
int displaying; /**< \brief if displaying already,
* i.e. if mng_display has
* already been called
*/
int finished; ///< if animation is finished
int global_time_ms; ///< current global time for MNG library
int anim_cur_time_ms; ///< current frame time in MNG animation
int anim_frame_duration_ms; ///< current frame duration in MNG animation
int show_cur_time_ms; /**< \brief current time in the show process,
* i.e. time of last demux packet
*/
int show_next_time_ms; /**< \brief next time in the show process,
* i.e. time of next demux packet
*/
int timer_ms; /**< \brief number of milliseconds after which
* libmng wants to be called again
*/
} mng_priv_t;
/**
* \brief MNG library callback: Allocate a new zero-filled memory block.
* \param[in] size memory block size
* \return pointer to new memory block
*/
static mng_ptr demux_mng_alloc(mng_size_t size)
{
return calloc(1, size);
}
/**
* \brief MNG library callback: Free memory block.
* \param[in] ptr pointer to memory block
* \param[in] size memory block size
*/
static void demux_mng_free(mng_ptr ptr, mng_size_t size)
{
free(ptr);
}
/**
* \brief MNG library callback: Open MNG stream.
* \param[in] h_mng MNG library image handle
* \return \p MNG_TRUE on success, \p MNG_FALSE on error (never happens)
*/
static mng_bool demux_mng_openstream(mng_handle h_mng)
{
mng_priv_t * mng_priv = mng_get_userdata(h_mng);
stream_t * stream = mng_priv->stream;
// rewind stream to the beginning
stream_seek(stream, stream->start_pos);
return MNG_TRUE;
}
/**
* \brief MNG library callback: Close MNG stream.
* \param[in] h_mng MNG library image handle
* \return \p MNG_TRUE on success, \p MNG_FALSE on error (never happens)
*/
static mng_bool demux_mng_closestream(mng_handle h_mng)
{
return MNG_TRUE;
}
/**
* \brief MNG library callback: Read data from stream.
* \param[in] h_mng MNG library image handle
* \param[in] buf pointer to buffer to fill with data
* \param[in] size size of buffer
* \param[out] read number of bytes read from stream
* \return \p MNG_TRUE on success, \p MNG_FALSE on error (never happens)
*/
static mng_bool demux_mng_readdata(mng_handle h_mng, mng_ptr buf,
mng_uint32 size, mng_uint32 * read)
{
mng_priv_t * mng_priv = mng_get_userdata(h_mng);
stream_t * stream = mng_priv->stream;
// simply read data from stream and return number of bytes or error
*read = stream_read(stream, buf, size);
return MNG_TRUE;
}
/**
* \brief MNG library callback: Header information is processed now.
* \param[in] h_mng MNG library image handle
* \param[in] width image width
* \param[in] height image height
* \return \p MNG_TRUE on success, \p MNG_FALSE on error
*/
static mng_bool demux_mng_processheader(mng_handle h_mng, mng_uint32 width,
mng_uint32 height)
{
mng_priv_t * mng_priv = mng_get_userdata(h_mng);
// remember size in private data
mng_priv->header_processed = 1;
mng_priv->width = width;
mng_priv->height = height;
// get total animation time
mng_priv->total_time_ms = mng_get_playtime(h_mng);
// allocate canvas
mng_priv->canvas = malloc(height * width * 4);
if (!mng_priv->canvas) {
mp_msg(MSGT_DEMUX, MSGL_ERR,
"demux_mng: could not allocate canvas of size %dx%d\n",
width, height);
return MNG_FALSE;
}
return MNG_TRUE;
}
/**
* \brief MNG library callback: Get access to a canvas line.
* \param[in] h_mng MNG library image handle
* \param[in] line y coordinate of line to access
* \return pointer to line on success, \p MNG_NULL on error
*/
static mng_ptr demux_mng_getcanvasline(mng_handle h_mng, mng_uint32 line)
{
mng_priv_t * mng_priv = mng_get_userdata(h_mng);
// return pointer to canvas line
if (line < mng_priv->height && mng_priv->canvas)
return (mng_ptr)(mng_priv->canvas + line * mng_priv->width * 4);
else
return (mng_ptr)MNG_NULL;
}
/**
* \brief MNG library callback: A part of the canvas should be shown.
*
* This function is called by libmng whenever it thinks a
* rectangular part of the display should be updated. This
* can happen multiple times for a frame and/or a single time
* for a frame. Only the the part of the display occupied by
* the rectangle defined by x, y, width, height is to be updated.
* It is possible that some parts of the display are not updated
* for many frames. There is no chance here to find out if the
* current frame is completed with this update or not.
*
* This mechanism does not match MPlayer's demuxer architecture,
* so it will not be used exactly as intended by libmng.
* A new frame is generated in the demux_mng_fill_buffer() function
* whenever libmng tells us to wait for some time.
*
* \param[in] h_mng MNG library image handle
* \param[in] x rectangle's left edge
* \param[in] y rectangle's top edge
* \param[in] width rectangle's width
* \param[in] height rectangle's heigt
* \return \p MNG_TRUE on success, \p MNG_FALSE on error (never happens)
*/
static mng_bool demux_mng_refresh(mng_handle h_mng, mng_uint32 x, mng_uint32 y,
mng_uint32 width, mng_uint32 height)
{
// nothing to do here, the image data is already on the canvas
return MNG_TRUE;
}
/**
* \brief MNG library callback: Get how many milliseconds have passed.
* \param[in] h_mng MNG library image handle
* \return global time in milliseconds
*/
static mng_uint32 demux_mng_gettickcount(mng_handle h_mng)
{
mng_priv_t * mng_priv = mng_get_userdata(h_mng);
// return current global time
return mng_priv->global_time_ms;
}
/**
* \brief MNG library callback: Please call again after some milliseconds.
* \param[in] h_mng MNG library image handle
* \param[in] msecs number of milliseconds after which to call again
* \return \p MNG_TRUE on success, \p MNG_FALSE on error (never happens)
*/
static mng_bool demux_mng_settimer(mng_handle h_mng, mng_uint32 msecs)
{
mng_priv_t * mng_priv = mng_get_userdata(h_mng);
// Save number of milliseconds after which to call the MNG library again
// in private data.
mng_priv->timer_ms = msecs;
return MNG_TRUE;
}
/**
* \brief MPlayer callback: Check if stream contains MNG data.
* \param[in] demuxer demuxer structure
* \return demuxer type constant, \p 0 if unknown
*/
static int demux_mng_check_file(demuxer_t *demuxer)
{
char buf[4];
if (stream_read(demuxer->stream, buf, 4) != 4)
return 0;
if (memcmp(buf, "\x8AMNG", 4))
return 0;
return DEMUXER_TYPE_MNG;
}
/**
* \brief MPlayer callback: Fill buffer from MNG stream.
* \param[in] demuxer demuxer structure
* \param[in] ds demuxer stream
* \return \p 1 on success, \p 0 on error
*/
static int demux_mng_fill_buffer(demuxer_t * demuxer,
demux_stream_t * ds)
{
mng_priv_t * mng_priv = demuxer->priv;
mng_handle h_mng = mng_priv->h_mng;
mng_retcode mng_ret;
demux_packet_t * dp;
// exit if animation is finished
if (mng_priv->finished)
return 0;
// advance animation to requested next show time
while (mng_priv->anim_cur_time_ms + mng_priv->anim_frame_duration_ms
<= mng_priv->show_next_time_ms && !mng_priv->finished) {
// advance global and animation time
mng_priv->global_time_ms += mng_priv->anim_frame_duration_ms;
mng_priv->anim_cur_time_ms += mng_priv->anim_frame_duration_ms;
// Clear variable MNG library will write number of milliseconds to
// (via settimer callback).
mng_priv->timer_ms = 0;
// get next image from MNG library
if (mng_priv->displaying)
mng_ret = mng_display_resume(h_mng); // resume displaying MNG data
// to canvas
else
mng_ret = mng_display(h_mng); // start displaying MNG data to canvas
if (mng_ret && mng_ret != MNG_NEEDTIMERWAIT) {
mp_msg(MSGT_DEMUX, MSGL_ERR,
"demux_mng: could not display MNG data to canvas: "
"mng_retcode %d\n", mng_ret);
return 0;
}
mng_priv->displaying = 1; // mng_display() has been called now
mng_priv->finished = mng_ret == 0; // animation is finished iff
// mng_display() returned 0
// save current frame duration
mng_priv->anim_frame_duration_ms = mng_priv->timer_ms < 1
? 1 : mng_priv->timer_ms;
} // while (mng_priv->anim_cur_time_ms + ...
// create a new demuxer packet
dp = new_demux_packet(mng_priv->height * mng_priv->width * 4);
// copy image data into demuxer packet
memcpy(dp->buffer, mng_priv->canvas,
mng_priv->height * mng_priv->width * 4);
// set current show time to requested show time
mng_priv->show_cur_time_ms = mng_priv->show_next_time_ms;
// get time of next frame to show
mng_priv->show_next_time_ms = mng_priv->anim_cur_time_ms
+ mng_priv->anim_frame_duration_ms;
// Set position and timing information in demuxer video and demuxer packet.
// - Time must be time of next frame and always be > 0 for the variable
// frame time mechanism (GIF, MATROSKA, MNG) in video.c to work.
demuxer->video->dpos++;
dp->pts = (float)mng_priv->show_next_time_ms / 1000.0f + MNG_START_PTS;
dp->pos = stream_tell(demuxer->stream);
ds_add_packet(demuxer->video, dp);
return 1;
}
/**
* \brief MPlayer callback: Open MNG stream.
* \param[in] demuxer demuxer structure
* \return demuxer structure on success, \p NULL on error
*/
static demuxer_t * demux_mng_open(demuxer_t * demuxer)
{
mng_priv_t * mng_priv;
mng_handle h_mng;
mng_retcode mng_ret;
sh_video_t * sh_video;
// create private data structure
mng_priv = calloc(1, sizeof(mng_priv_t));
//stream pointer into private data
mng_priv->stream = demuxer->stream;
// initialize MNG image instance
h_mng = mng_initialize((mng_ptr)mng_priv, demux_mng_alloc,
demux_mng_free, MNG_NULL);
if (!h_mng) {
mp_msg(MSGT_DEMUX, MSGL_ERR,
"demux_mng: could not initialize MNG image instance\n");
free(mng_priv);
return NULL;
}
// MNG image handle into private data
mng_priv->h_mng = h_mng;
// set required MNG callbacks
if (mng_setcb_openstream(h_mng, demux_mng_openstream) ||
mng_setcb_closestream(h_mng, demux_mng_closestream) ||
mng_setcb_readdata(h_mng, demux_mng_readdata) ||
mng_setcb_processheader(h_mng, demux_mng_processheader) ||
mng_setcb_getcanvasline(h_mng, demux_mng_getcanvasline) ||
mng_setcb_refresh(h_mng, demux_mng_refresh) ||
mng_setcb_gettickcount(h_mng, demux_mng_gettickcount) ||
mng_setcb_settimer(h_mng, demux_mng_settimer) ||
mng_set_canvasstyle(h_mng, MNG_CANVAS_RGBA8)) {
mp_msg(MSGT_DEMUX, MSGL_ERR,
"demux_mng: could not set MNG callbacks\n");
mng_cleanup(&h_mng);
free(mng_priv);
return NULL;
}
// start reading MNG data
mng_ret = mng_read(h_mng);
if (mng_ret) {
mp_msg(MSGT_DEMUX, MSGL_ERR,
"demux_mng: could not start reading MNG data: "
"mng_retcode %d\n", mng_ret);
mng_cleanup(&h_mng);
free(mng_priv);
return NULL;
}
// check that MNG header is processed now
if (!mng_priv->header_processed) {
mp_msg(MSGT_DEMUX, MSGL_ERR,
"demux_mng: internal error: header not processed\n");
mng_cleanup(&h_mng);
free(mng_priv);
return NULL;
}
// create a new video stream header
sh_video = new_sh_video(demuxer, 0);
// Make sure the demuxer knows about the new video stream header
// (even though new_sh_video() ought to take care of it).
// (Thanks to demux_gif.c for this.)
demuxer->video->sh = sh_video;
// Make sure that the video demuxer stream header knows about its
// parent video demuxer stream (this is getting wacky), or else
// video_read_properties() will choke.
// (Thanks to demux_gif.c for this.)
sh_video->ds = demuxer->video;
// set format of pixels in video packets
sh_video->format = mmioFOURCC(32, 'B', 'G', 'R');
// set framerate to some value (MNG does not have a fixed framerate)
sh_video->fps = 5.0f;
sh_video->frametime = 1.0f / sh_video->fps;
// set video frame parameters
sh_video->bih = malloc(sizeof(BITMAPINFOHEADER));
sh_video->bih->biCompression = sh_video->format;
sh_video->bih->biWidth = mng_priv->width;
sh_video->bih->biHeight = mng_priv->height;
sh_video->bih->biBitCount = 32;
sh_video->bih->biPlanes = 1;
// Set start time to something > 0.
// - This is required for the variable frame time mechanism
// (GIF, MATROSKA, MNG) in video.c to work for the first frame.
sh_video->ds->pts = MNG_START_PTS;
// set private data in demuxer and return demuxer
demuxer->priv = mng_priv;
return demuxer;
}
/**
* \brief MPlayer callback: Close MNG stream.
* \param[in] demuxer demuxer structure
*/
static void demux_mng_close(demuxer_t* demuxer)
{
mng_priv_t * mng_priv = demuxer->priv;
if (mng_priv) {
// shutdown MNG image instance
if (mng_priv->h_mng)
mng_cleanup(&mng_priv->h_mng);
// free private data
if (mng_priv->canvas)
free(mng_priv->canvas);
free(mng_priv);
}
}
/**
* \brief MPlayer callback: Seek in MNG stream.
* \param[in] demuxer demuxer structure
* \param[in] rel_seek_secs relative seek time in seconds
* \param[in] audio_delay unused, MNG does not contain audio
* \param[in] flags bit flags, \p 1: absolute, \p 2: fractional position
*/
static void demux_mng_seek(demuxer_t * demuxer, float rel_seek_secs,
float audio_delay, int flags)
{
mng_priv_t * mng_priv = demuxer->priv;
mng_handle h_mng = mng_priv->h_mng;
mng_retcode mng_ret;
int seek_ms, pos_ms;
// exit if not ready to seek (header not yet read or not yet displaying)
if (!mng_priv->header_processed || !mng_priv->displaying)
return;
// get number of milliseconds to seek to
if (flags & 2) // seek by fractional position (0.0 ... 1.0)
seek_ms = (int)(rel_seek_secs * (float)mng_priv->total_time_ms);
else // seek by time in seconds
seek_ms = (int)(rel_seek_secs * 1000.0f + 0.5f);
// get new position in milliseconds
if (flags & 1) // absolute
pos_ms = seek_ms;
else // relative
pos_ms = mng_priv->show_cur_time_ms + seek_ms;
// fix position
if (pos_ms < 0)
pos_ms = 0;
if (pos_ms > mng_priv->total_time_ms)
pos_ms = mng_priv->total_time_ms;
// FIXME
// In principle there is a function to seek in MNG: mng_display_gotime().
// - Using it did not work out (documentation is very brief,
// example code does not exist?).
// - The following code works, but its performance is quite bad.
// seeking forward
if (pos_ms >= mng_priv->show_cur_time_ms) {
// Simply advance show time to seek position.
// - Everything else will be handled in demux_mng_fill_buffer().
mng_priv->show_next_time_ms = pos_ms;
} // if (pos_ms > mng_priv->show_time_ms)
// seeking backward
else { // if (pos_ms > mng_priv->show_time_ms)
// Clear variable MNG library will write number of milliseconds to
// (via settimer callback).
mng_priv->timer_ms = 0;
// Restart displaying and advance show time to seek position.
// - Everything else will be handled in demux_mng_fill_buffer().
mng_ret = mng_display_reset(h_mng);
// If a timer wait is needed, fool libmng that requested time
// passed and try again.
if (mng_ret == MNG_NEEDTIMERWAIT) {
mng_priv->global_time_ms += mng_priv->timer_ms;
mng_ret = mng_display_reset(h_mng);
}
if (mng_ret) {
mp_msg(MSGT_DEMUX, MSGL_ERR,
"demux_mng: could not reset MNG display state: "
"mng_retcode %d\n", mng_ret);
return;
}
mng_priv->displaying = 0;
mng_priv->finished = 0;
mng_priv->anim_cur_time_ms = 0;
mng_priv->anim_frame_duration_ms = 0;
mng_priv->show_next_time_ms = pos_ms;
} // if (pos_ms > mng_priv->show_time_ms) ... else
}
/**
* \brief MPlayer callback: Control MNG stream.
* \param[in] demuxer demuxer structure
* \param[in] cmd code of control command to perform
* \param[in,out] arg command argument
* \return demuxer control response code
*/
static int demux_mng_control(demuxer_t * demuxer, int cmd, void * arg)
{
mng_priv_t * mng_priv = demuxer->priv;
switch(cmd) {
// get total movie length
case DEMUXER_CTRL_GET_TIME_LENGTH:
if (mng_priv->header_processed) {
*(double *)arg = (double)mng_priv->total_time_ms / 1000.0;
return DEMUXER_CTRL_OK;
} else {
return DEMUXER_CTRL_DONTKNOW;
}
break;
// get position in movie
case DEMUXER_CTRL_GET_PERCENT_POS:
if (mng_priv->header_processed && mng_priv->total_time_ms > 0) {
*(int *)arg = (100 * mng_priv->show_cur_time_ms
+ mng_priv->total_time_ms / 2)
/ mng_priv->total_time_ms;
return DEMUXER_CTRL_OK;
} else {
return DEMUXER_CTRL_DONTKNOW;
}
break;
default:
return DEMUXER_CTRL_NOTIMPL;
} // switch (cmd)
}
const demuxer_desc_t demuxer_desc_mng = {
"MNG demuxer",
"mng",
"MNG",
"Stefan Schuermans <stefan@blinkenarea.org>",
"MNG files, using libmng",
DEMUXER_TYPE_MNG,
0, // unsafe autodetect (only checking magic at beginning of stream)
demux_mng_check_file,
demux_mng_fill_buffer,
demux_mng_open,
demux_mng_close,
demux_mng_seek,
demux_mng_control
};