Commit def1cf72 authored by Arun Raghavan's avatar Arun Raghavan Committed by Tim-Philipp Müller
Browse files

pbutils: Add MPEG-4 Video profile/level extraction

This adds code to translate the profile_and_level indication from the
MPEG-4 video (ISO/IEC 14496-2) headers to a string profile/level. The
mappings are taken from the spec and Wireshark's code, and might need to
be expanded on.

https://bugzilla.gnome.org/show_bug.cgi?id=617314

API: gst_codec_utils_mpeg4video_get_profile()
API: gst_codec_utils_mpeg4video_get_level()
API: gst_codec_utils_mpeg4video_caps_set_level_and_profile()
parent e4bd09f0
......@@ -526,3 +526,185 @@ gst_codec_utils_h264_caps_set_level_and_profile (GstCaps * caps,
return (level != NULL && profile != NULL);
}
/**
* gst_codec_utils_mpeg4video_get_profile:
* @vis_obj_seq: Pointer to the visual object sequence for the stream.
* @len: Length of the data available in @sps.
*
* Converts the profile indication in the stream's visual object sequence into
* a string. @vis_obj_seq is expected to be the data following the visual
* object sequence start code. Only the first byte
* (profile_and_level_indication) is used.
*
* Returns: The profile as a const string, or NULL if there is an error.
*/
const gchar *
gst_codec_utils_mpeg4video_get_profile (const guint8 * vis_obj_seq, guint len)
{
/* The profile/level codes are from 14496-2, table G-1, and the Wireshark
* sources: epan/dissectors/packet-mp4ves.c */
/* These are a direct mapping from the integer profile id -> string. Profiles
* 0x6, 0xe and 0xf can correspond to more than one profile depending on the
* second 4 bits of vis_obj_seq[0], so they are handled separately. */
static const char *profiles[] = { "simple", "simple-scalable", "core",
"main", "n-bit", "scalable", NULL, "basic-animated-texture", "hybrid",
"advanced-real-time-simple", "core-scalable", "advanced-coding-efficiency",
"advanced-core", "advanced-scalable-texture",
};
int profile_id, level_id;
g_return_val_if_fail (vis_obj_seq != NULL, NULL);
if (len < 1)
return NULL;
profile_id = vis_obj_seq[0] >> 4;
level_id = vis_obj_seq[0] & 0xf;
if (profile_id != 6 && profile_id < 0xe)
return profiles[profile_id];
if (profile_id != 0xf && level_id == 0)
return NULL;
switch (profile_id) {
case 0x6:
if (level_id < 3)
return "simple-face";
else if (level_id < 5)
return "simple-fba";
break;
case 0xe:
if (level_id < 5)
return "simple-studio";
else if (level_id < 9)
return "core-studio";
break;
case 0xf:
if (level_id < 6)
return "advanced-simple";
else if (level_id > 7 && level_id < 0xe)
return "fine-granularity-scalable";
break;
}
return NULL;
}
/**
* gst_codec_utils_mpeg4video_get_level:
* @vis_obj_seq: Pointer to the visual object sequence for the stream.
* @len: Length of the data available in @sps.
*
* Converts the level indication in the stream's visual object sequence into
* a string. @vis_obj_seq is expected to be the data following the visual
* object sequence start code. Only the first byte
* (profile_and_level_indication) is used.
*
* Returns: The level as a const string, or NULL if there is an error.
*/
const gchar *
gst_codec_utils_mpeg4video_get_level (const guint8 * vis_obj_seq, guint len)
{
/* The profile/level codes are from 14496-2, table G-1, and the Wireshark
* sources: epan/dissectors/packet-mp4ves.c
*
* Each profile has a different maximum level it defines. Some of them still
* need special case handling, because not all levels start from 1, and the
* Simple profile defines an intermediate level as well. */
static const int level_max[] = { 3, 2, 2, 4, 2, 1, 2, 2, 2, 4, 3, 4, 2, 3, 4,
5
};
int profile_id, level_id;
g_return_val_if_fail (vis_obj_seq != NULL, NULL);
if (len < 1)
return NULL;
profile_id = vis_obj_seq[0] >> 4;
level_id = vis_obj_seq[0] & 0xf;
if (profile_id != 0xf && level_id == 0)
return NULL;
/* Let's do some validation of the level */
switch (profile_id) {
case 0x3:
if (level_id == 1)
return NULL;
break;
case 0x4:
if (level_id != 2)
return NULL;
break;
case 0x6:
if (level_id > 5)
return NULL;
break;
case 0xe:
if (level_id > 9)
return NULL;
break;
case 0xf:
if (level_id == 7 && level_id > 0xd)
return NULL;
break;
}
if (profile_id == 0 && level_id == 8)
/* Simple Profile / Level 0 */
return "0";
else if (profile_id == 0 && level_id == 9)
/* Simple Profile / Level 0b */
return "0b";
else if (level_id <= level_max[profile_id])
/* Levels for all other cases */
return digit_to_string (level_id);
return NULL;
}
/**
* gst_codec_utils_mpeg4video_caps_set_level_and_profile:
* @caps: the #GstCaps to which the level and profile are to be added
* @vis_obj_seq: Pointer to the visual object sequence for the stream.
* @len: Length of the data available in @sps.
*
* Sets the level and profile in @caps if it can be determined from
* @vis_obj_seq. See #gst_codec_utils_mpeg4video_get_level() and
* #gst_codec_utils_mpeg4video_get_profile() for more details on the
* parameters.
*
* Returns: TRUE if the level and profile could be set, FALSE otherwise.
*/
gboolean
gst_codec_utils_mpeg4video_caps_set_level_and_profile (GstCaps * caps,
const guint8 * vis_obj_seq, guint len)
{
const gchar *profile, *level;
g_return_val_if_fail (GST_IS_CAPS (caps), FALSE);
g_return_val_if_fail (GST_CAPS_IS_SIMPLE (caps), FALSE);
g_return_val_if_fail (vis_obj_seq != NULL, FALSE);
profile = gst_codec_utils_mpeg4video_get_profile (vis_obj_seq, len);
if (profile != NULL)
gst_caps_set_simple (caps, "profile", G_TYPE_STRING, profile, NULL);
level = gst_codec_utils_mpeg4video_get_profile (vis_obj_seq, len);
if (level != NULL)
gst_caps_set_simple (caps, "level", G_TYPE_STRING, level, NULL);
return (profile != NULL && level != NULL);
}
......@@ -48,6 +48,16 @@ gboolean gst_codec_utils_h264_caps_set_level_and_profile (GstCaps * ca
const guint8 * sps,
guint len);
/* MPEG-4 part 2 */
const gchar * gst_codec_utils_mpeg4video_get_profile (const guint8 * vis_obj_seq, guint len);
const gchar * gst_codec_utils_mpeg4video_get_level (const guint8 * vis_obj_seq, guint len);
gboolean gst_codec_utils_mpeg4video_caps_set_level_and_profile (GstCaps * caps,
const guint8 * vis_obj_seq,
guint len);
G_END_DECLS
#endif /* __GST_PB_UTILS_CODEC_UTILS_H__ */
......@@ -3,6 +3,12 @@ EXPORTS
gst_codec_utils_aac_get_level
gst_codec_utils_aac_get_profile
gst_codec_utils_aac_get_sample_rate_from_index
gst_codec_utils_h264_caps_set_level_and_profile
gst_codec_utils_h264_get_level
gst_codec_utils_h264_get_profile
gst_codec_utils_mpeg4video_caps_set_level_and_profile
gst_codec_utils_mpeg4video_get_level
gst_codec_utils_mpeg4video_get_profile
gst_discoverer_audio_info_get_bitrate
gst_discoverer_audio_info_get_channels
gst_discoverer_audio_info_get_depth
......
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